1. Use T-code: GR52
2. Enter your report group and click on reports
3. Select the report you want to delete
4. Finally. click on delete row which is the first tab with the red sign.
To assign it to report group two, use GR52.
Enter report group 2
Click on reports
In the next screen, use the drop-down menu under report to select the report you want to assign to report group 2 and save.
Yes you can change to another library. It is just a matter of deleting the report from the library it is currently in and assigning it in the new library.
Proceed as follows:
1. First copy the report to the new library.
2. Afterwards, delete the report from the old libary using GR34.
Hope the above solutions helps.