Hardware:
2x m3x6mm
2x m3 hex nuts
1x craft knife

Use 0.2mm nozzle if possible with arachne wall slicer

The back screw can be tightened as much as desired; the tightness of the screw nearest to the blade controls how hard it is to swing out the blade.

(Feel free to use a small amount of threadlocker if the screw at the front undoes itself - make sure not to add too much, otherwise the knife will be impossible to disassemble)

When using Rev2, the blade can be easily swapped by unscrewing the screw that's nearest to the blade. The KnifeHolder parts should then be taken out. Replace the blade, then re-assemble.