Alero Power Steering Pump Install

1999 Oldsmobile Alero 3.4L V6 4-door sedan w/approximately 147,000 miles

I am looking for advice on installing an aftermarket power steering pump with variable steering. I've removed the old pump and pulley, but I am having trouble removing the variable steering actuator from the old housing to install in the new housing. If I can't remove it, I could just replace it but would this be a sensor that a local parts store would carry? I'm open to ideas at this point. I see two nuts on the sensor after removing the clips from the back and removing the sensor coil. I have applied the whole "left to loosen" rule of thumb with a crescent wrench but the nut just is not budging.

Can someone share their experiences with this type of job?

Thanks.

You need a very large boxed end wrench or a large crestent wrench and a big vise to hold the pump.

Here is a procedure i put together with some pics .
http://www.automotiveforums.com/vbulletin/showthread.php?t=901624

hope that helps.