The z-axis bolt of the makergear m2 and its counter nut are not so easy to access with conventional screw wrenches or drivers.
This pair of tools allows for independently turning the bolt and the nut at the same time. They are used in a nested configuration. I also upload a modified version of the MakerGear M2 Tool Holder
by 3DPrinterHowTo that also hosts the z-axis bolt driver plus counter nut tightener. Look for "MakerGear M2 Tool Holder (z-axis screw driver support)"
Slice it with support structures using the alignment in the file.