I have ruined one removing them from my car initially. Fortunately, I had replacements on hand. Whoever had installed, or reinstalled mine, had used trim tape, or butyl tape under the moulding.
My friend had suggested making a removal tool using an old bottle opener with masking tape covering the strategic points. Unfortunately, it didn't work for me, but I did bend a piece of metal into a sort of hook configuration and sharpened the end so it would fit underneath the lower moulding. Because mine were stuck on so well, one was damaged and the other came off in one piece.
The replacements that I was able to obtain from a junkyard Cutlass Cruiser came right off with the method that I first described...hand manipulation.
I don't recommend removing the drip rails. Once they're off...they're gone...finitto.