Change waterpump and refit and tenion fan belt on 318 tds

hi just bought a bmw 318 tds 1996 the fan belt is off and the water pump is jiggley (at least i think its the water pump its behind big plastic wheelie fan type thing) (please excuse the technical jargon) How do I remove these and what do I need is this a complete water pump needed or just a bearing and how mechanical does the repairer need to be, I'm fairly good but do I need to leave it with a real mechanic. thanks.