To remove a file from the repository first remove it from your directory then use:
cvs remove stubs.py
The file is removed when you next commit.
If you've removed and committed the remove but want to restore the file, then find the version of the removed file:
$ cvs status stubs.py =================================================================== File: no file stubs.py Status: Up-to-date Working revision: No entry for stubs.py Repository revision: 1.3 /var/cvs/projects/kton/Attic/stubs.py,v
So this is version 1.3. We restore it using:
$ cvs update -j1.3 -j1.2 stubs.py U stubs.py