[dba-Tech] Renaming two box

I finally got myself a genuine server (compaq proliant 2 cpus raid yada yada
yada. For simplicity's sake I would like to rename said server to X, but
another box on the network is currently called X, so I need to rename it to
Y and then move all the databases from there to the genuine server. With any
luck, after the renaming all the Access ADPs and .NET solutions will not
notice that X and Y have traded names. How can I go about this?

Server = w2k Advanced Server, currently called Y.
MyDev = wxp Pro, housing a default instance of SQL2k (whose databases I want
to move to Server)
2 other boxes have apps that point to X, which after the clever rename will
automatically point to Y.

I'm not going to to anything without a backup and a plan. Advice?

TIA,
Arthur