I found out AS calls the "trim" by the name "GARNISH"!
I ordered them new from local AS dealer. Shipped to my door was cheaper than fuel!
I have the old ones as I saved for measuring! If you want specs I can measure and try to post.
Be careful working overhead by protecting your eyes and lungs if necessary.
To remove garnish/trim, there are 4 screws on front and rear. Two hold on the "shade" on one end and two on the other shade end. When you pull off the shade you will see two more screws on each end. They were hidden by the shade!
Carefully remove screws until almost out on both sides. Then hold trim while removing screws. Trim should separate from roof easily but if not, gently pry down.
Clean bug carcasses out.
Install new trim!
You will want to predrill the trim to minimize splitting chance. Just lay the old one next to new and mark.
There is a block of shim wood on each side that is screwed to the skylight metal framing. Might check that for rot/ dryness so it doesn't split on you. If necessary you can replace the wood with special AS part which you purchase with Unobtanium currency. Or a suitable pine, for or spruce scrap.
Also, when you put trim in place, slightly push up to put a little squeeze on roof to help seal.