I have used 1/8" nylon chord in the past on most windows, liberally spray 409 or other cleaning agent on the rubber. It will act as a lubricant. overlap the chord by 6 " or so. Then with a helper on the outside gently pushing, pull the chord back on itself around the window. The window will nearly fall in.

If you are using an h-channel with a lock, all that is needed is your fingers.

Scott

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me