Check your tracks for a master link you might not have to beat a pin out.
Inspect the recoil spring for broken coils.
After you get tracks open slide idler a head.
When you have idler in the place where its been running measure the distance between the adjuster flange and the spring flange,if this is over 5 inches you will have to do something about your tracks.
To remove yoke 4 bolts on idler 4 bolts on adjuster flange.
Pull flanged cylinder out of spring,piston with seals will be inside. piston will have 2 flat split rings and a seal and snap ring on end .There is a o-ring on the flange that needs to be replaced.
If you want PM me and I can talk you thru this where you don't have to break the tracks.
Good luck
Bob