Probably the best way is to use your heat and use it to slightly heat up the material (to get the advesive to release) as you pull it off. More then likely you will have to do a light sanding over the whole fuselage with a fine grade sandpaper to clean up your work. Don't worry about the color left behind (if you are going to use the same color in MonoKote) just make it smooth. Then follow up with a tack cloth to remove the dust. This will help the MonoKote stick better. Sorry you had to learn the hard way but hey, least you won't make the same mistake again....Right?

Cheers,