Earlier this spring I had to replace the water pump on my 103. Before I replaced the pump, the small hose between the water pump and the engine developed a crack so I wanted to replace it before I was left stranded. I had to do the same process as if replacing the pump. So I tore it down and replace the hose and reassembled. To my horror, you guessed it the water pump started leaking through the weep hole behind the pulley shaft.
You better plan on 4 ~ 6 hrs for the first time.
You will need to remove the following.
1. Radiator
2. Radiator fan
3. Belt
4. Pulleys from power steering pump & water pump
Air Cleaner assy.
5. Disconnect wiring running to the engine & injection sensors in the main
wiring harness back to the firewall. Some of the electrical connectors
will crack due to the high heat and cooling over many years. Be
carefull!
6. Injection lines and pump
7. Intake manifold
There are two bolts for two stablizer brackets under the intake
manifold that can only be reached from under the car on the drivers
side. You will need a long extension and a ujoint for your ratched to get
them loose.
8. You will need to take the bolts out of the power steering unit to gain
access to the water pump bolts.
9. Remove the old pump and replace.

P.S. Don't forget to drain the antifreeze and remove the transmission
cooling lines before removing the radiator.
I hope my experance will help your job go smoother and faster than mine did.

Regards