Overhaul

Hello, I live in Arizona and my home and windows are about 26 years old.  Can you help me with what parts I would need to order including springs etc?

So I took one out,,, here are the photos.  The top of the windows don't appear to have springs, just these same plastic pieces without the rollers.  Also, I have some larger windows but haven't taken them apart to see if there are just multiples of these on the bottom.  Thank you!