Launching Service Designer for 10.2.500.x -- (Missing)

I am trying to find and launch the service designer tool to rebuild method signatures in C#, for the CsgPlugIn functionality, that are different from 10.1.600.x.

I can’t find the tool and I am not sure what the signatures (parameters) must be.

The "CallContext.Current.GetMainContext() does not exist anymore.

Any one know how to get the service designer and/or know the correct code for the constructor?

Thanks