Change z axis creality K1

hello
one of the 3 Z axis threaded rods of a k1 arrived bent
how to disassemble this axis to change it
i did not find anything except a complete disassembly of the plate
thank you for your help!

They are held in place by the collars and the top bearings. The rear collar cannot be accessed without removing the whole back panel.

To remove one of the fronts.
Remove the Z-belt. Check here for service videos

Loosen the set/grub screws on the collar; z lead screw should be able to be removed through the bottom of the printer.

When reinstalling, make sure to lift up the lead screw and push the collar down and tighten.