I used a razorblade and heatgun, once I got the mats off and the leftover adhesive was still there I put some warm soapy water to help loosen it up and got the majority of it off with that. Anything in hard to reach spots or leftover that didnt get taken off by the razorblade I used some of this:
Here is mine. A work very good to take the mats off initially and then I took Goo Gone and sprayed it on and let it sit overnight and then just cleaned it up to get all the he says woof but the same exact tool 5 minutes in the thing is spic and span