HOW TO: Remove headlight sealant
I took my headlights apart to do some modifications using the heatgun suggestion which worked well. Once you get it started it seems to pry apart fairly easily.
I don't like the idea of leaving the old sealant behind and then re-heating it to put the lens back on. It just seems like a perfect set-up for leaks down the road.
I picked up some Krud Kutter Ultra Power Specialty Adhesive Remover for about $5 at Home Depot..
Using a paper towel, I was able to clean most of the gunk off the clear plastic lens. Be careful though, these solvents can and will dull plastic on contact.
Then I dripped some all along the channel on the black housing and let it sit for about 10 min. The sealant becomes extremely soft and fairly easy to scrape out with a combination of flathead screwdriver, utility knife, and gentle finger pulling.
Just wanted to share as some people seem to leave and re-use the sealant and others (like me) want to remove as much of it as possible.
I've attached a photo of the solvent and also what the sealant looks like when removed.
Hope this helps someone.