I switched my instrument cover and also found it was glued on the front edge.
The glue was very slightly pliable, it took a heat gun and some work with a sharp edge tool to cut thru the glue. I recall it took me almost an hour to get the old cover seperated from the glue on the insert. I ended up damaging the old cover slightly, but as I was replacing it I was not as careful as I could have been.
Once I had the old cover removed I spent additional time removing all the old glue that was still on the insert lip. I installed the new cover without any glue as the covers have a lip that overlaps the instrument panel lip. So far no issues with rattles or squeeks from the new panel.
After writing this and thinking about the amount of hassle in getting the glue off and the parts seperated, It may be easier to just modify the new part to accept the 911 cluster!!!!