I should have included instructions, sorry...

First clean the suface of the existing sills and wipe with alcohol. That will make a nice clean surface. Depending on the temperature (below 45 is probably a good point) you may want to "warm" the new sills with a hair dryer a bit (careful if you are using a heat gun, they get very hot and could melt the polyethelyne). Then just peel and stick. It is a good idea to match up the end closest to the back edge of the sill, then gently lay down the top edge to align with the sill then press down. They will come up easily if you don't get it lined up immediately. You can then reposition till you get it right.

Thanks again for your orders. Glad you like them.

Karl