how to install the 23-041 roller assy.

Well, it would depend on how it's attached. The 23-041 can be attached via two methods: by screw, or by the hooks. If yours is attached by screw you should be able to just unscrew them. If it is attached by the hooks, you will need to use a pair of needle nose pliers (or a similar applicable tool that you are comfortable using) and work the hooks out. In either instance, we recommend removing the door entirely and placing it on a flat stable surface.