A screen roller will work. A plastic putty knife if you use the round end of the handle. Install the bottom of the W/strip into the retainer 1st. Then the top with the roller, etc, etc. You just don't want to use anything sharp. To keep them from pulling off, use a small bead of 3M "black" W/strip adhesive applied to the center of the metal retainer, not the W/strip. Black takes a while to set up so you have time to make adjustments as needed. Try not to pull the W/strip went you install them. And like wise you don.t what them to bunch up either. As pulling them will make them smaller if you get the idea....I hope.