I cant speak for the 616 engine, but I have done a waterpump or two on the 617 engne (one more cylinder).

Remove fan shroud
Loosen alternator and Power steering pump so you can loosen the belts
10MM closed end wrench for the bolts on the fan (you may need to grind it)
10MM rachet for the waterpump, I think its 5 bolts.
Tighten them evenly
Re tighten the belts, but not too tight!

Its a pretty simple job.