Soldering the connector is very low risk. No need to worry about heat from an iron. In manufacturing, modern PCBs have their lead-free solder flowed in an oven at temperatures in excess of 220 C.

Reconnecting or accessing the files using just office supplies is possible provided there is access to a fine-point soldering iron or the means to DIY one. In this situation, I’m thinking of office supplies as “things you might find in an office” - not just rubber band, paperclip, eraser, pocket lint.

I’ve cut USB cables and soldered the 5V, D+, D-, and GND wires to corresponding pads on the flash drive to recover data plenty of times.

When a connector is torn or snapped off, it is not uncommon for those pads to be lifted and even for some of the traces to get peeled off the board. 5V and GND are usually pretty big, but the traces for the data lines are often hair thin.

In those cases, someone in the scenario you describe would need to attach the wires to another point that those traces origin connected to, or they might need to scrape away some if the mask (green layer) to expose a contact point to solder to.

Worth mentioning that those four contacts make a USB 2.0 (500Mbps) connections. For USB 3 (5Gbps) there are 5 more contacts, for a total of 9.

USB Type C has 20 contacts and will require a microscope to work with.

Since the USB standards are backwards compatible, you could still recover data from a USB-C device by recreating just the four USB 2.0 contacts - albeit slowly.

It’s a difficult enough task that I would probably be unable to suspend disbelief.

That said, if your hero has some time and a soldering kit it would be fairly doable and relatively believable. Also keep in mind that most flash drives now have the contacts for the USB port as part of The printed circuit board that has the actual storage on it and usually the actual storage would be encased in resin, at least with a good flash drive.

The cheap ones, you could totally do this though.

This is a fun thought experiment. If I’m understanding correctly, you’re writing a story where the character has a flash drive with important information. They have to remove the end to prevent the bad guys from getting access to it, then later replace the end to access the information themselves. Here’s my pitch (disclaimer: don’t actually try to do this. It would probably work, but if you have actual important files on a flash drive, this isn’t by any means how you should be trying to get at them)

For removing the end, soldering would be safe if they have access to a soldering iron. If it’s an emergency scenario, then I’d say just snap the plug off. It’s a bit risky depending on how the drive is made, but if it’s done deliberately by someone who knows what they’re doing, then I would say they could plausibly take off the USB connector without permanently damaging any of the guts.

For connecting the drive later, find a spare usb cable and cut it in half. It shouldn’t be hard to find one in an office. Even cutting the plug off a wired mouse or keyboard would work. Use a pocket knife or pair of scisors to strip the outer insulation off the cut end. This exposes four small wires. Strip the ends of those as well. Now, you just need a way of attaching each wire to the correct spot on the circuit board in the flash drive. Soldering would be best, but in a pinch, I’d look around the office for some of that sticky clay stuff they use to hang up posters. Pre-chewed gum might also work. Lay the stripped end of each wire over the correct spot on the board, then put a blob of the sticky stuff on top to hold it in place. Plug the other end into a computer, and you should be good to go.

Office supplies? I think it is plausible but far-fetched - depending on the office.
Quick? Likely? Easy? probably not.

I assume you have enough scissor and stuff to open it and get at the PCB.

Any good MacGyver these days has a TS-80 style iron in their pocket - but if not they might bodge together a soldering iron from any heater / kettle / hair dryer (bathroom hand dryer) or even just some electrical resistors.

Shave down any copper wire thin enough and you get a heating element that will work for a short period of time - the solder just has to melt before the iron does.

Marry the heating element to the right size thermal mass tip, to allow it t get to about 350 degrees C annd deiver enough heat to melt the blob. you also need a heat proof electrical insulator to isolate the tip. I think ceramic usually, a Kettle heater will have something like that.

MacGyver can do thermodynamic heat flow / heat capacity calculations in his head anyway so the tip design is no big deal - in reality trial and error at this step is where you run out of time and materials.

Alternatively, maybe hack the laser printer, it’s probably not hot enought ootb, but if you can manually cause the laser to dwell until the solder melts it might build up enough heat? - it only needs to work for four blobs of solder anyway.

Once you have the heat source sorted out, you need flux to reflow the old solder that’s on the pads. I think vaseline / petroleum jelly will work in a pinch. Some office worker, or even first aid kit might have that as lip balm or something. The HQ of Deus Ex Machina Ltd. has a pine tree in the atrium with some rosin seeping out of the bark.

Anyway, with the heat and flux sorted you just clip the tail off a usb mouse and solder the wires on to the PCB .

Having important files on a USB stick is by definition risky.

How risky is to de-solder an usb plug if the flash-drive contains important files? It would be relatively safe for someone capable, or the heat is way too risky for the chip/content?

If you’re halfway competent, it’s almost risk-free.

Also there’s any (MacGyver like) way to quickly access the file or reconnect the plug without a solder while only having access to office supplies?

That’s unlikely.

I don’t know what your story is, but if a key part of the plot is removing a USB fob’s connector to hide files, and quickly establish contact with the old plug to read them, you need to rethink that part of the story because the whole thing sounds very contrived to me.

There are point probing tools on AliExpress that could likely be used to extract the data without having to solder, but you’ll be spending like 50$ pre tariff.

I agree, someone competent can do it risk free. One possibility, depending on how macguyer or prepared the character needs to be is to use pogo pins. Perhaps magnetically held in place.

there’s dosdude1 soldering away on NAND chips; this should be a walk in the park even for a hobbyist.

as to macgyvering, the S in USB is for “serial” and such a connection needs very few wires, three if I’m not mistaken. so an absent USB connector could be fixed temporarily with clips and wires and such.