The usual acces method to the D0 cvs repository is to setup d0cvs and use the addpkg command. To do this one needs a valid kerberos ticket. Right now there is no cross-autentification between CCIN2P3 and FNAL, so you don't have a valid ticket for FNAL.
In the simplest case where you'd like to issue an 'addpkg package' command, i.e. with no option , you can use 'getpkg package'. This is a script in /afs/in2p3.fr/throng/d0/scripts (that should be in your path) that will make a copy of the package in the release you have setup'ed.
For all other cases, you would have first to create a public key once, send it to Alan Jonckheere and use setup d0sshcvs. There are subtleties, details can be found here .