Shifter Cable on 2008 Jeep Patriot

What is the level of difficulty to change out the shifter calbe and what should the estimate be?

Asked by for the 2008 Jeep Patriot
The skill level is moderate. Estimated time is 2.5 hours. A/T Shift Control Cable 5273433AD $24.95
Procedure to replace cable:
Disconnect the negative battery cable. Remove shifter cable at transmission bracket. . Remove the nut on the shifter cable to shift lever.
Remove the grommet at the bulkhead. Remove the shifter. Squeeze clip at cable. Pull cable from bracket at bulkhead. Loosen the hold down bolts at the air bag module. Pull the cable through the bulkhead into the engine compartment.
This is what they are currently doing to my Jeep at dealership. It would pop out of gear when I'd put it in first. Now that they replaced this part, now they are saying the "gear box" is broken and need to replace that too! I am afraid to say "what next" :(