CVS Question

I have loads of files checked out as user Foo, because that's the user the install doc said to use. A couple of these neded tweaking, and now need to be committed. User Foo apparently lacks write permission to accomplish this. I've changed my CVSROOT env var to user Bar, who should have rights, but when I do 'cvs login', it prompts me for the password for Foo. Is there way to resolve this other than getting the PTB to give Foo write permission? (Not out of the question, but the PTB are pretty busy, as I understand, so it would be better if I could do something.)