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@WickedFog said I can't stress enough to use good tools. I primarily use Wera and Wiha hexes, but Dyanmite, Pro-tek, MIP, Bondus and others are all good brands. If you get any tool and they are loose, bent or deformed send them back. Good tools save you time, bad tools cause you grief. You really only need a few sizes. I got my Wera tools from McMasters and the two primary sizes (2,2.5mm) are about $11 total. If you throw 2 common ones in the others you talking about $20 +tax and shipping.
https://www.mcmaster.com/products/hex-drivers/ultra-grip-screwdrivers-9/
These are Wiha tools. The grip is smaller and you won't get the same torque from them but they definetly live up to "precise".
https://www.mcmaster.com/products/hex-drivers/precise-control-screwdriver-sets/
Don't use ball end tools for super tight screws there is less surface area (higher pressure) and it's more likely to strip.
Don't use power tools. You need to feel the metal deform while you strip it out. It makes it much more satisfying while you spend the next 4 hours disassembling your rig for one stupid screw.
For anything that doesn't come right out (and is in metal) I use a mini-torch. You don't have to kill it, just 10-15 sec at a time, try it again, Repeat until the thread lock or gunk clears up.
https://www.harborfreight.com/butan...=362&msclkid=cbc29690a3c012844a9ff3e323eee781
The soldering iron is extremely useful for parts in or around plastic, because you can control the heat more.
Worst comes to worst you can drill the head out. Then you might be able to grab the end of it with some Vise Grips. If not you'll need to order some new parts.