Regenerating (inside-out) service to add operation from new function

I created a service provider in ABAP based on a function group (Inside-out definition) so that each function module is an operation in the service.

Now I have added another (RFC-enabled) function to the function group, and want to add this as an operation to the service.

The problem is that there seems to be no way in SE80 to do this. (In SPROXY, you have the option to regenerate a service interface when it has changed). It seems the only way to do this is to delete and recreate the service provider, but that means losing data, like the operations I have renamed etc.

Do you know of a better way? Maybe there is a transaction or program to regenerate an inside-out service?