Thanks everyone for the advice. I started to remove the sill (from the back), and immediately realized that it's already cracked. I didn't continue any further, as I may be able to get a new sill from Tesla - it's listed as "chrome", but they think it's the black (fake) leather and silver one like I have. I'll know soon, and it will be covered under my extended warranty so I'll only pay the $100 deductible. What I'm wondering is: has anyone ever reinforced a sill to strengthen it before installing? If so, how did you do it? If what Tesla has isn't a match, I could maybe get this one off without yet more damage, and fix/reinforce it. Many thanks for your further thoughts!