VNB4T 1963 I Need Help Removing Switch Housing From Handlebar Housing

I am restoring the 1963 Vespa 125 that I bought in 1965.  It has a broken front brake lever mount which is integrated with the switch housing.  I want to replace this but do not know how to remove the switch housing from the handlebar housing.

I have completely disassembled the scooter except for this item and need to do this before I can start the painting.  Also, should the new switch housing be installed before or after painting the handlebar housing?

Thank you