Hello,
We have been told that the Harmonic Balancer on our 1989 (3.8L LE) Bonneville is going bad. They want to replace the crankshaft sensor, tensioner and Harmonic Balancer for a hefty price of $800 Cdn. Instead of forking out this cash, could anyone tell me how difficult it would be to do it at home.
Are special tools needed, do we need to lift the engine up to get the part off? I have found conflicting information on different websites.

Any help is appreciated, thank you.

That is a hefty price tag indeed. Several on this forum did it in the last few months and they are still healthy.
THis may help:this is from 1993, but it is typical.
www.avigex.ca/xport/ckps.jpg
www.avigex.ca/xport/ckpsremoval.jpg
www.avigex.ca/xport/ckpulley.jpg

The access is from the wheel well. May be renting the puller would make things easy. They all did it without the complement of other special tools. ANd once you paid yourself the trouble of getting there, changing the cam sensor too might be a good idea.