1990 F150 gear replacement.

[ajr2000]

I'm posting this for my dad's 1990 F150. Lately it has been real hard to start. The starter gears have been skipping. I removed the starter today today to realize that the outer housing which holds the bearing was totally cracked off and missing. Fortunately, the started can be replaced for free for life from autozone. (already needed 3 starters in 6 years) However it appears that the gear the starter engages has become damaged? How hard is this to replace? Does the tranny (standard) need to be dropped? What would be the process for that?

Also, any idea what a garage might charge to have this done.

My dad thanks you all, he been stuck driving his 78 Camaro all week.