do you have altiris? or sms? or some endpoint sw/patch solution? Its smc -stop, place new sylink.xml, and smc -start. Before you go down this path, which is bascially rebuiding your SEPMs (either from scratch or prefer back up database, and re-install new SEPM, and restore old database), make sure you test out SNAC and are going to deploy SNAC. there are some tools you can get from support as well like sylink swapper but it crawls a subnet basically. and make sure you have public liveupdate in their LU policies so they can get updates.
I would advise you talk to support as well.
Best way is enterprise sw management agent that you already use imo.