I was able to remove the old from the used EZL - I used the cap from a bottle of water to get it off of there. The car body itself had none on it. The old EZL appeared to have a thin layer of clear plastic on the outside of the compound. I just removed that and put an entire small tube of the compound on it ("zig-zagged" it back and forth) and put it on the car. It was kinda thick and I could not get it to spread evenly. Hopefully it will be ok.

Thanks!