Well you may need a satellite receiver, or you might want to try a computer with an HD card, if you are ok with the learning curve on that.
You didn't say what analog receiver you had or what lnb, but you might be able to use them. the receiver slaved to your new satellite receiver, to drive your actuator or motor.
lnbs are cheap and most guys now seem to go for the voltage control lnbs that set polarity electronically instead of mechanically.
I would do it. The hard installation work is done. Start by going out to your dish and then slap a level on the mast. If it is still plumb, so far so good. If your cable is buried, you might have to replace it, because gophers apparently think it is delicious. It's ok to bury it, but the better practice is to run it through a pvc conduit.
I would then spray some penetrating oil on all the bolts and nuts. I'd get some string and run it from edge to edge in a + shape. If the dish is still straight the strings will be straight and meet in the middle.
I'd measure from the edge of the dish to the scalar hole in a few places. If the measurements are exactly the same, you are looking good. If not, well there may be some bending needed.
Good luck.