Some time we may need to change the query inside the existing workbook for some reasons such as query assigned incorrectly, migrate system from PQ1 to WBP, query obsolete. There is no way to converse the existing workbook to the new workbook automatically. It is required to do one time manual job. The best way is creating from scratch. However, if user wants to use existing workbook, it is possible but it may be possible to have an error.
Execute the new report in the existing workbook
Adjust the layout to be exactly the same as existing one (all columns and rows need to be exactly match if the workbook have pivot or calculation)
Remove the existing query (crosstab) at component tab, right click on crosstab and select "Delete"
Move the new report to the same position of previous query by clicking on pencil on "Cell".
Note: All manual calculation should be automatically adjust. If not, you may have to do the calculation manually like refresh the pivot to get the new name of the characteristic.
