Attachment for window sash

Thanks for posting. Looks like you're showing us your friction shoe. See our 15-104 Caradco Friction Shoe. Go over the specs listed on the product page and let us know if you think this could work as a replacement for you. Keep in mind that if you need to replace your springs as well, we cannot help--you will need to contact a local mill work for assistance. 

That's a good question. I won't lie to you, it will be either very frustrating or a five minute one-and-done. It requires removing the jamb liner from the window and sliding the old shoe out from the bottom. It looks like your old jamb liner is only screwed in, but I'm not sure what else may be involved in removing it. It could be as simple as unscrewing it and taking it out, but I've seen some cases where it required taking the entire frame apart, as well. The only way to know is to try it out and see what works!