[HairTooLongToo]

Bought a door panel to give this a try, and... I'm stuck.

So the door card structure is nothing more than a huge piece of molded cardboard. The insert is leather and padding wrapped around its own piece of cardboard. The board of the insert is flatly adhered to the board of the door card itself.

This is where I'm stuck. How do you unglue two pieces of paper product that's been flat glued without destroying one or the other? I've been using a heatgun and trim tools to pry around the edges (which will lift) but not sure how to get them unstuck in the center where I assume the glue is.

Now obviously lots of example here of custom inserts so there's a way. I don't know what it is though. Now this is a non-M e90 rear door with leather, but I doubt it's any different on the M.

Attached pic show through the speaker hole shows the two boards, adhered together.