Window and wall cleanup - Join

A very simple tip, (based on an online q)

Here was a window at the junction of two walls like:

The goal is to get a display was like:

1. Go to the Wall Joins ( )tool in the tool bar.
2. Select the wall joint.
3. Keep pressing the Next button in the option bar until Revit shows something like:
   
4. Click on Modify to exit the command