I've just fitted a set of these. Piece of the proverbial wee wee. You don't need to use a heat gun, just lift a corner of the original ones and it'll all come off in one strip, easy. You need to remove the plastic trim on the inside of the door sill. This just clips off, no tools needed. Then pull the door seal up and give the whole area a good clean. Pull out the small plastic 'bung' on the outer edge of the sill with a pair of long nose pliers. The new sills are sided so make sure you get the right one! Pull half the backing off the new sill and simply place it where the old one was, it's a perfect fit too. Then remove the rest of the backing and smooth it all down, getting any air bubbles out as you go. Refit everything and you're done. Took me about 30min start to finish just take your time or it'll look poo. Looks the dogs too.