I am preparing to buy a 2002 Chevy Blazer, 4x4, 4.3L V6, and auto transmission. The buyer is telling me that the oil pump needs replaced. He has told me that the entire engine must be pulled just to access the pump. I was wondering if that was true, or if there is another way of replacing it?

 

I think if you had a 2" body lift, between that and picking up the motor a ways you could get it done. Other than that, dropping the front axle/differential would be required. Those are about your only two options that I can think of that would be easy aside from pulling the engine out completely.
I've only pulled a few, but the hardest part is making sure you don't break anything. Most of the time we've had it pulled in 2-3 hours though.

 

+1. Those are your only real options.