I did mine last year and used sikaflex. I tried to peal out as much as I could then cleaned well and re caulked. It doesn't look factory new but has held up well when traveling this spring on three different occasions covering a couple thousand miles. It is a tedious job and if I was rolling in money I would gladly pay someone to do the work.
Basically at the camper center I use they sell you a plastic putty knife because a metal one will tear up the aluminum. After that its about scoring the old putty with a box cutter(making sure not to go to deep (don't score the aluminum) and carefully pulling out all the caulk you can. After that clean it with mineral spirits or they also strongly recommend using windex. Then re caulking. I also used a lot of the putty tape in a roll. Not sure what its called but its great for where the steel frame edging meets the aluminum.
I also rebuilt my lower wings on my 98 lance. After rebuilding I used the 4 inch wide eternabond on the inside of the wings just like vinyl siding. Working from the bottom up. There is no way water will ever get in there again.
JMHO