Hi Billy,
take a look at cousinsUK. They have a scheme about components of 2824-2, 2836-2 etc and there you can find all you need to do that change.
These are the parts you need (to get a H4):
- Cannon Pinion With Drive Wheel, Height 2.70mm (ETA2500242H270)
- Fourth Wheel Centre Seconds, Height 5.55mm (ETA2801227H555)
- Hour Wheel, Height 1.76mm (ETA2600255H176)
Of course you must have a little bit knowledge about movements.