Hi,
I think replication can be one of the easiest option.
But go through this note as well:
Note: Replication is an option, if you do replication and remove the old server that is the Primary SEPM, in future if you want to do replication you will not be able to do so.
Check this article to learn more about it.
https://www-secure.symantec.com/connect/articles/hot-move-sepm-one-server-another-server