Get a high quality masking tape and tape the back sides of the doors. Masking is the hardest and most time consuming part so take your time. The prep is always the hardest part with bedliners. Make sure you degrease with acetone or comparable sand lightly, re-acetone, mask. Remember to mask everything you do not want to get bedliner on as this stuff sticks well. Hours of prep are required for 10 minutes of painting/spraying. Take your time and you will be fine. I had a buddy who did his whole xj in black hurculiner only to have it start to fall of months later with bad prep. Good luck and take lots of pictures when you are done.