You sound annoyed. I have sympathy. Sometimes it is not easy to directly find an answer because you don't know the terminology.
Graphisoft doesn't explain how to remove a library part because it is so obvious: Throw away the part by placing it in the trash. It is gone.
Or so we would wish. Except that GS wants you to keep the original library untouched, so for official Archicad Library parts, they make it tricky.
The basic library comes in a special format - almost like an archive - called a library container. This is hard to edit for a reason: because as the Archicad library evolves, users mess up thier libraries, losing functionality. Ask me: A long, sad story. The container approach protects the integrity of the library and lets you swap up to a newer library with confidence, since any objects you add or change are added in a folder that must be manually incuded in the library load and are unaffected by upgrading.
It is a pain to throw away an object "contained" so. You go thru this process: Using the library manager, extract the library to a new folder. Throw away the part you don't want. Create a new container.
But you should always keep the original library container.
Alternatively, you could extract all of the contained elements into a new folder and thro away the parts from there.
Further study: Page 23, Reference manual
Dwight Atkinson
