We've found that if it's not in your capabilities (CAME, CAMOE etc.) then you can't perform the task... Our workaround is finding some third part organisation who does, and have them carry out the work (though this probably doesn't help your specific situation)
If you obtain some sort of authorisation / NTO from the OEM, and possibly the TC holder of your aircraft to carry out specific tasks (Galleys / APUs / Airstairs etc.) then your NAA may allow you to carry out these tasks, but its probably best to square this with the relevant authority and your QA department...
Hope this helps in some way, but if your looking for some sort of quick and easy way to work to the CMM, then you may be out of luck.