I just replaced my mast, which required taking the whole thing out of the trunk to get it apart. I had to chuck one end in a vise and pound on it, cuz the aluminum tube was glued as well as screwed to the plastic housing. Stuck the thing in a deep freeze for a day to help break the glue bond.

Once I had it apart, I found an incredible amount of dirt on the plastic worm gear of the mast and on the drive gear that pushes it. There actually was nothing wrong with the mast itself, not bent or anything. Just wouldn't come up more than one section due to the dirt blocking the gear.

The mast is only 22.00 at IPD and they include instructions on how to replace. But if your mast isn't bent, you can probably just pull it apart and clean the whole thing. Not really hard at all.