replacing o2 sensor on '93 V6/3.1L

My oxygen sensor is bad and needs to be replaced. The main question is can I replace it myself. I've been told it's not hard to do, but this was by the guy who fixed it thus far (a coolant leak fixed by an amateur mechanic led to a vacuum seal catastrophe that knowledgeable guy fixed - long story, really) and I figure it's possible that his expertise may influence the his use of the concept of 'easy.'
I'm not a total dummy when it comes to mechanical things, but I'm just worried about what I may get myself into. Will I need special tools? Is the sensor hard to get to? Is there only one sensor and which one is it? I did a parts search on O'Reilly's website and it came up with three categories - Lambda Oxygen Sensor, Oxygen Sensor (Fuel Injection), and Oxygen Sensor (Emissions). I don't know what to make of this.
Or any websites with this info would help. I can't find any specific info or threads with the same issues. Also, I'm not sure if o2 sensor replacement on other years of this model will be the same.
Any help is appreciated. I suspect the Haynes would help as it did on my Tempo years ago, but I can't really spare the $$ if I won't end up using it. Thanks.

Slow down here this is routine, 7/8 box wrench or o2 socket, sensor is in the pipe coming off the rear cylinder head. Just to a parts store and get the normal one for your car.