SAP System migration from one server to another.

Our SAP system is migrating from old server to new server because of provider change.
In SAP they are changing System number and system ID to new values.
We have sync project and all matching rules defined in mapping are based on DistinguishedName.
Because of changes in SAP all distinguished names are changing in SAP system.

Now my question is what is the best practice to proceed with this migration of SAP system.
Could you please let me know what is the best practice we should follow here.