A trick i learned when doing my window I found if you put ya seat back cover your face and hands and push it frew with ya feet as it might shatter but mine didnt

this way you still have your rubber in tacked. It also better if you have some one else there on the passinger side aswell.
Then get your new window from a brakers yard next to nothing i fink £20 tops. Then place you rubber on it and then get a big bit or wire yea thats right wire like a tv power wire but enuf to go around the window and still a lot more left over. place the middle of the wire at the middle bottom of the window so when u put the window in its place you have to bits of wire comeing from above your head were the the mirra is/was then once the window is all in place put the wire from the inside of the car and watch the rubber seal fold over the frame of the car once you pulled the hole lot of wire out. Go on the out side and just lightly tap the bits of rubber still out of place and it should just pop in
hope that helped lol