Great way to replace a lever - easier than what I did! Thanks for sharing it. Looks like a good addition for this thread: Random tricks, share your best little tips & shortcuts.
I just replaced a worn out lever (ovalized pivot hole) on my PX. I did something similar. The objective is to unbolt the lever and replace it without disconnecting the pinch bolt at the clutch cable arm. I taped the existing lever closed against the grip and then wrapped a piece of baling wire around the clutch arm and rear brake cable housing. Then I took the tape off the lever. Without any cable tension, it's a simple unbolt and swap out of the old lever and replace with the new lever. Remove the wire and it snaps back into place.