[paulspickupparts]

If you are not trying to save the glass it is relatively easy to get the glass out.

Lay over a trash can and remove the glass with a hammer. Safety glasses and gloves recommended .

If you want to save the barrel screws and glass then lightly heat the barrel screws with a torch. Then some penetrating oil. Spray them down and give them a good wrap with a screwdriver , clutch head of whatever they have. Remove .
Once the screws are out get a 1 x 4 on end and knock off the bottom sash. With one hand holding the glass with upper frame (upside down) tap both ends of the upper frame. Usually it will pop off . If not or if someone used urethane or something else you may have to use some lacquer thinner or other measures to loosen.
New barrel screws are available if you mess them up.
Get the right size setting tape and revers the order . As someone mentioned there is a rubber seal on the bottom sash that many forget. Not hard but takes a little time.