if u wanna re-trim it, easy as pie, using a contact adhesive in a spray, spray the liner then lay the new material on it and using some sand or dirt, put it on top of some plastic on the fabric to apply even pressure over night. next morn, remove sand, curl ends around and using a short profile staple, fasten it down or use the glue again with tape as this part isnt seen. and done. will look heaps better.