I don't know if there is a formal guide for that process. But it's fairly simple.
1. Install the new version of PGP Command Line on your new system.
2. License PGP Command Line on your new system.
3. Copy over your keyring files (pubring.pkr, secring.skr) from your old server to the appropriate location on the new server (that is, put them where PGP Command Line expects to find them -- you can run "pgp --version --verbose" and it will tell you where that is).
4. If you have made any changes to your preferences file PGPprefs.xml, re-apply them to your new preferences file.
Regards,