Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
If the fixture is marked for a certain maximum watts, and you are using the right watts, it should not be melting or smelling bad.
Is it really in a bookshelf, ie: poor air flow over or around it?
I would lift it up on little blocks to get some air flow under it before cutting in to it. Cutting it might void the warranty.