It's not really a complicated job, but it needs a bit of care and attention. This is more of a general guide, as I don't know the details of the Ram engine...
- Basic Socket set
- Clicking Torque wrench
- Workshop manual for your truck (mainly for the torque wrench settings)
- Assorted spanners, screwdrivers etc.
Disconnect the battery.
Begin by draining the coolant - save it and dispose of it properly, don't let it leak into watercourses or onto the ground, especially if you have pets, as it's toxic to animals.
Remove the upper cooling hoses. Remove the serpentine/alternator/fan belt(s). Remove the valve cover(s) and cambelt/chain covers.
Disconnect electronic sensors, spark plug leads and fuel lines.
Lock the crankshaft in position (again, the manual should specify how for your engine), and mark the positions of it, the camshaft and the belt/chain. Remove the cambelt/chain.
Remove intake and exhaust manifolds.
Double-check that there's nothing left attached to the head(s).
Slacken the head-bolts in the order specified by the manual.
Remove the head bolts, then lift the head straight off.
Take the head(s) to a machine shop and get them checked for flatness. Clean off the old headgasket from the block. If it's a wet-liner engine, be very careful not to disturb the liners.
Refitting is then the reverse of removal. Make sure the camshaft is aligned with the marks you made before fitting the head. Use new head-bolts, and tighten them in the order specified by the manual - this will often be an odd sequence involving tightening to a certain torque, then going round again to a tighter torque, and often going round again turning an extra 1/4 turn or similar.
Check and double check the timing as you refit the belt/chain. Turn it by hand a couple of turns and make sure the marks still align. Refit the rest of the stuff. Check it all again, and refill the coolant. Start the engine, and let it warm up to temperature, checking frequently for anything amiss.
You may need to re-tighten the head bolts after a certain mileage, but again the manual should specify that.