It is not a big deal if you're mechanically inclined. Even if not a direct replacement. You just need to make sure that the anchors for the mounts are screwed into solid points of the RV. Regardless if you choose a direct replacement, you still need to make sure your mounts are weatherproof. Otherwise, your asking for trouble later.
Do it right. Or have someone install it with a guaranty. You will be better off. Otherwise, you can do it if you're sure of yourself. Your call.