Changing Water Pump

My friend has a 3cyl Metro with a noisy water pump and he wants me to help him change it. He has a third party manual that covers Metro and Sprint. I see you have to remove the timing belst to change the pump. He just had a new belt put on so all we need to do is remove it and set timimg marks.

My concern and question is how difficult is it to align the belt when we remove it to change the pump? Are the timing marks easy to find and align properly? Any suggestions?