How to replace Data Source for existing report?

Anonymous In power bi desktop go to query editor, select your table and on the right hand side under Applied Steps click settings icon. You can also without going to query editor - go to File -> Options and settings -> Data source settings >Right click data sources and chnage source.

go into Edit Queries.  Find the table/query you want to change.  Go to the first step in the Query (always called Source) and change it there.