I just did that but while i was working on it something shifted and now the bolt holes are 1/2 inch off...
tighten the bolts on the alternator and have a helper lift
bottle jack under the harmonic balancer
2x4 as a lever under alternator
couple of 2x4 across the gunnel, loop a rope thru the lifting eye and around the 2x4s, stick a long screw driver thru the rope and twist it
it doesn't take much force. when you get done -- tighten the bolts on the other side of the mount, sounds like they might be a little loose