10a. First, lay a piece of tape on the line where you want the fender to meet up with the body. Then set the fender onto the body where you want it. Have a friend hold it in place while you tape a second piece of tape on to the fender matching the line of the first piece of tape. When done, the two pieces of tape should lie directly over top one another as you can see in these photos. Now ,you have a perfect line to trim the fender to the exact size you need.