You have to use a gear puller. They're on there pretty tight. Be aware though...the gears are on a splined shaft and the splines are REALLY fine. There is only 1 way that the gears will go on the splines (one spline is welded together, IIRC) so if it don't fit, don't force them. Once you have the gears out of the way you can remove the rest of the bolts behind the front bearing retainer and pull the retainer and rotors out all at once.
Is that off of a V6-71 or an Inline? They are different. Also, if you plan on using it in a vehicle application, be aware that most of the parts have to be changed over. About the only thing you'll be re-using will be the case, and even then if there's any big scratches in the sides, it'll be useless. I have bought & sold probably 50 of these things (most were Inline 6-71's, but I also had a few 10's and V8-71's) and the last 8-71 blower I had I was going to use on a 460 in my old truck. Once I got all the prices of having it rebuilt, reworked, and refurbished to work in my application, I could have bought a new "kit" from BDS.
Is that off of a V6-71 or an Inline? They are different. Also, if you plan on using it in a vehicle application, be aware that most of the parts have to be changed over. About the only thing you'll be re-using will be the case, and even then if there's any big scratches in the sides, it'll be useless. I have bought & sold probably 50 of these things (most were Inline 6-71's, but I also had a few 10's and V8-71's) and the last 8-71 blower I had I was going to use on a 460 in my old truck. Once I got all the prices of having it rebuilt, reworked, and refurbished to work in my application, I could have bought a new "kit" from BDS.