Need help to only print one small part I'm in dire need to reprint a small chunk of a print that got messed up during print because the support for it broke which I cannot explain whatsoever.

Anyway. I need to edit the STL file and I don't know what tool to use since Blender is definitely not user friendly for just a simple cut and past.

Anyone got an idea on what I should try to do? Reprinting is definitely out of question since that would take at least another 20 hours, that I haven't got, to reprint the whole thing and I would also just waste a lot of PLA.
Alright so I asked in my facebook group and a friendly fellow game me the tip to use Meshmixer from AutoCAD and then check a video on Plane cut. I only needed 3 simple cuts and the piece I needed was all ready to print. :) 40 Minutes to print and only 3g of PLA to spend :)