A ratcheting cargo strap makes a very effective "third hand" when I'm working by myself on projects like this. Just wrap the strap around the part that needs to move a little, find a convenient anchor point, ands ratchet away!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!