I asked the same question about a year ago, the only answer I got was to cut or dig it out. I used a utility knife and screwdriver to get mine out. It took about 1.5 hours. Have fun, thats some tough sealant.
I've done this twice to two different Ultra tour paks and a hair dryer helps a lot to loosen the silicone HD uses to seal the light sockets inside the tour pak. The heat made a huge difference. I used a hair dryer since it's not as tricky to use as a heat gun. Wear gloves 'cause the hair dryer will heat the silicone enough to make bare fingers hurt when you pull the pieces off; use a putty knife and flat blade screw driver or equivalent to score and scrape the silicone.
Carl
Last edited by Harleypingman; 03-05-2010 at 10:22 AM.