Originally Posted by mary and bob
Uhaul used the "fold-in" lock strip on one side window. Lube it with some dish soap. A hook type tool or small screw driver, or old putty knife that doesn't have sharp corners may help. I just sent Pam a NAPA # 3470 hook tool to use on her window replacement, ask her how she liked it. I took one window out that used that type lock strip just to measure the opening size, it went back together easy, less work than the separate lock strip.
We installed our new UHaul windows
from the inside, which was on the same side as the locking tab/ lockstrip. So there was a little more 'give' in the weatherstripping on the inside. We used some old heavy duty butter knives to poke and pry and 'negotiate' the window into the rubber weatherstripping inch by inch. That Napa tool could have been used instead of a butter knife, if needed. It was absolutely indespensible to get the lockstrip in.
Here is a picture of our 'tools'. The cup and paintbrush had super soapy water that we used to butter the groove when we were installing the lockstrip in once the window was in the weatherstripping. The rubber mallet was used to make sure the gasket was seated tightly into the perimeter.