Advanced Editor for Published Data Sets

I am trying to replace data sets people have used in their reports which are direct to the data warehouse (sql views), with published ones I have created.

Previously I would add in the published data set, then copy over the code from the advanced editor and replace the code for the existing data set.

Now it seems I cannot see the advanced editor when I connect to published datasets, which is this?

What is the best way to resolve this situation if I can no longer use this method.