If we want to move any one or two packages publish/subscribe is ok. If we want to do code migration 

the best is to use wMDeployer.

 2) You can do it in 2 ways. 

              1. wmDeveloper. 

              2. Admin Console

DEVELOPER : You can copy and paste or drag and drop a package from one server to other.

From Admin console : We can do this by replicating a package and then send or Publish the package to another server.

To do this you should be a member of Replicator ACL.