Thanks for posting, Ian. It looks like you have a Chamberlain window that was made in the late 1980's. You are right in observing that the sashes aren't made to come out. It's frustrating, but that's just how these windows are made. We have a way around that, but let's talk about the balances first.
I see you bought our
S500-23 spiral balances. Did this match your old balances? If so, you will need to reuse the old sash clips attached to your window. I actually see them still installed in the sash. You might need a pair of needle nose pliers to straighten out the fork that catches on the balance bow tie.
As for balance installation, you will need a friend. With someone helping you, you will need to drop the new balance in from the top of the sash, screw it in at the top, then let the spiral drop down. You will then raise the sash and, while someone holds the sash in the open position, spin the spiral up to the bottom of the sash. Finally, with our
75-004 tool, give the balance about three turns to charge it and lock it to the end into the sash clip.
Let me know if you have any more questions.
