hi friends. im new here. where can I get a good waterpump and is hard to replace myself?

 

Might as well change the timing belt, thermostat during the water pump replacement procedure.

A hint of that
HOW TO REPLACE A THERMOSTAT & WATER PUMP Audi Quattro - YouTube

Audi A6 Timing belt and water pump - YouTube

Audi A6 1998 - 2004 Front Lock Carrier Service Position (Radiator Support) - YouTube

 

I use Amazon.com and rockauto.com. Also look at blauparts.com and fcgroton.com.
Get a timing belt kit, water pump and thermostat.
Also put new genuine Audi/VW coolant in. Around $25 gal concentrate from dealer. Mix with distilled water.