When I did mine a few years ago the Boots were still good so I just cleaned out the old grease and repacked it with the recommended Swepco molly grease.
I went to the local Princess Auto (Harbour Freight equivalent) and for $1.99 bought a pair of wire snips and filed the jaw sides flat as well as the snip face. You only need about 1/4 inch flat on each side of center for the snip face. This was my special tool and it worked fine. In the photo the surface rust areas are the spots I filed to flat, you can't see the snip face so well.
The clamps I used are in the photo. I can't remember if they are the Porsche ones or are the after market from a local supplier. I do remember they were both a PITA but the photo ones worked the best. You wrap them around the boot as tight as possible by hand (and then so more) then crimp the square piece with the special tool.
