Hi Ted,,,When i got to that point on mine,,I just laid the rubbers out in the sun(calif. sun)
and gently slid the glass into 'em,, and using lotso soapy water,, and patience,,set 'em into the opening as much as you can by hand,then with more soapy water and a ,,,kind of a hooked screwdriver, with you on the inside and the lil woman on the outside pushin on the glass(gently),,just go around the perimeter slowly bringing in the rubber "lip" into place.
Its all about patience and a lotta soapy water.
Thats what worked for me.
Im sure someone else will come along and have a different method.
Good Luck To Ya,
Marty