Dennis, the OP is asking about the engine circulating pump!I'm going to rebuild my AQ131C pump.
As long as the body is in good shape, it goes like this;
1. remove two 16mm ID bushings, carefully
2. press in new bushings carefully.
3. Replace seal.
4. Optional, replace steel shaft with new one.
Looks like this
http://www.go2marine.com/docs/1/1/2/0/112038F-p.jpg