I would make a wooden block just about the right size to keep the trem forward. A clamp might slip off. Push your bar down and put the wooden block behind your trem block.
Get a string winder.
New strings.
Move all your saddles back as far as they will go, this way when your
intonation is out you know which way to move the saddle ! Also if you undo the locking bolt slowly enough (with a slightly slackened string) the tension in the string will pull the saddle forward for you.
Measure between 5th fret fretted and 17th fret fretted.
When you do get the intonation right measure the distance between each saddle and the edge of your trem in case you ever need to take it to bits again. This will give you a head start next time.
I think there was an intonation tool available, an Ibanez made one. Has that been discontinued ?
