Crestline window sash spring part
Do you have this part? Are there any instructions on how to remove the sash/ channel so I can replace the part?
We don't have this exact friction shoe, but see our 15-104. Could you possibly get this to work as a replacement?
Oh, I'm sorry! I overlooked that part of your post. I'm not sure if your shoe works exactly like our 15-104, but in my experience the only proper way to replace these is to take apart the window. This isn't an easy task and I would recommend seeking the help of a local professional if you don't have any past experience with these windows.
The only other alternative is to heat the track up a bit so you can squeeze the new shoe in. This isn't that easy either, and there's a risk you can permanently warp the track if you aren't careful. I would only do this if you have no other choice.
What you want to do is use a heat gun or hair dryer to heat up the track near where the old shoe is sitting. When the track is soft enough you should be able to remove the old shoe and install the new one.
If you choose this method, be extremely careful not to over heat and damage the track. If you damage the track, your window will no longer function. Once the jamb is warped, there's no fixing it. It'll be ruined.