In Power BI using Power Query Editor you can change the Data source. Power BI provides many ways to change data source, let’s understand with an example.
Approach 1:
Step-1: Go to Home tab in Power BI header menu, under this click on Edit Queries.

Edit Queries in Power Bi
Step-2: Power Query Editor window opens then click to Data source setting.

Datasource setting
Step-3: Now select your existing datasource which you want to change and click on Change Source.

Select Data Source
Step-4: SQL Server Database screen appears, now write your server & Database name then click to OK.

Change Datasource Power Bi
Step-5: Now click on close button then click to Close & apply left side top corner.
Make sure your new database contains all old database tables, queries with same name & definition, otherwise your report visuals will not work.
Approach 2:
Step-1: Under Power Query Editor, select your Dataset then click on source setting icon.
Step-2: After that SQL server Database screen appear, write your server & Database name and you can also change your query from here.
Step-3: After all steps click to OK, then Close & apply.
How to replace Data Source for existing report?
Step-1: Under Power Query Editor, select Dataset then click to Advance editor.

Change Data Source Advance Editor
Step-2: Advance Editor window appears, now change your server & database name and click on Done.

Advance Editor Power Bi
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