That's not a good "learner" because it will be more difficult to disassemble it and you won't have a accurate feel of how it comes apart vs how it goes together. Heat and pullers may be needed when otherwise not called for. It might be able to be rebuilt and put in use again, it will just be a little more difficult. If upon disassemble, you discover more damage, you will need experience to make a judgement call on wether to proceed. Some times the shafts have built in surfaces that the gear clogs rest or spin on and if badly pitted or corroded, you might experience excelerated wear when back on use. Gear whine might be experienced as well. With break in, it will quite down.... In this case, maybe not.
I would give this one away and upgrade to something else...
1975 CJ-6 304 T15 Dana20 30/44 3.73
1983 CJ-8 258 T5 300 30/44 3.31 Looking for full or half hardtop buy or trade
1986 CJ-7 Laredo 4.6 stroker T5 300 30/44 3.31
1986 TJ-7 Trail Jeep project in the works
2003 Inca Gold TJ Rubicon