On off constraint while welding / unwelding the rigid bodies


say I have two rigid bodies connected to each other via a constraint (only rotation allowed)
So, the objects relative orientation is varying in the game because of other factors.
Now, at some moment, I need to weld them as they are in their current orientation, so they will act like one rigid body.
Likewise, I need to un-weld them, and so on…

Any suggestions how to do it via blueprints?