So I just bought a wrecked 2003 Dakota to use the rear end. I checked and made sure the gear size and ratio were correct but didn't even think about the brakes... what all do I have to do to change from my 2002 drum brakes to 2003 disk brakes?

 

Hydraulics don't need much change, many people don't do anything.

The parking brake cables have to be modified but I'm not sure how. May be easier to pull those off the donor truck.

 

P.S., if the front spindles are intact, swap those over too.

The 2003/2004 brake package is MANY TIMES superior to the 97-02 brake package.