I am not sure if a Cat is the same but on my Dresser this is what I do to colapse the adjuster.
Remove the grease zerk and check valve it is threaded into at the base of the track adjust cylinder.
I also remove the pressure relief valve near the same location.
If you have tongue hitch on the rear of the dozer put some blocks under it.
Start the dozer and raise the front end up with the blade. The rear will rotate up on the blocks. The front tracks will be well off the ground and the rear tracks will be just clear of the ground. But most important your slack will be on the bottom which will make it easier to remount the track if you can. Get it all lined up on the idler and rollers and sprocket.
Use a come along, your tractor, a winch (I use a logging winch), your wifes car etc, to pull the front idler back to colapse the cylinder. If you have a six way blade you can put a block between the blade and front idler then angle your blade back to push the idler and colapse the cylinder. But you have to do this before you get the dozer jacked up of course.
Be careful - don't go to far something will break.
Getting the track back on is usually a chalange. Good luck.