The bearing we refer to as the throwout bearing is called the pushrod bearing by the Harley parts manual.
To replace the throwout bearing, remove the cover on the right side of the transmission (the chrome cover that the dipstick and the clutch cable go into).
The throwout bearing is on the pushrod assembly that is inside the mainshaft (the mainshaft is the shaft toward the rear).
It will pull out by hand.
Remove the snap ring, the bearing is between the two washers.
I have a manual for `89 softail, it does not show the throwout bearing in the illustration for the `89 clutch, but it does show it in the illustration for the `90 clutch…
Anyway, the worst part of this job is that on some bikes you must remove the exhaust.