i normaly install dp on the new or test server and install same patches as on the production. because you have same install directory, you just can stop DP services on boths systems. then copy DB40, Config folder from production to the new server (i normal delete those two folders on the test system before). after this is finished, you can start dp services again
because you changed server name, you have to run command
omnidbutil -change_cell_name
after that, verify with
omnidbutil -show_cell_name
it should show you the new hostname (fqdn) now.
You can now open gui to check if everything is ok (also omnidbcheck -extended, omnidbcheck -dc).
the only thing which will not work is to start any backups because of ip change. licenses are ip bound. but i think this does not matter for the tests you are doing.
Also you have to modify cell_info file. edit the line with cell and installation server to fit your new hostname
this should be all