So if you are having no issues changing to a leadscrew only has the real benefit of increasing the max speed of your Z axis. If you want to change over it depends on what gantry version you have. For the newer “525” style you only need to replace one of the XYZ parts to the newest version, add the leadscrew & nut, appropriate coupler, and 2 m3x10 screws, after the hardware just update to the correct firmware.
If you are not at the “525 version” the one that looks like it does now. You will need a more extensive upgrade.