regearing is not as simple as just turning some bolts. they need to be set up juuuuust so or you can burn them or the bearings up in a short amount of time. if you're a very handy guy and you want to buy the specialty tools and try your hand at it, it's not impossible. just challenging. I'm sure there are plenty of youtube vids on it.
but if it were me, this would be a great opportunity to upgrade that axle too. my dana 35 grenaded itself under my then 2wd 88 on 30" tires. just started spitting ring gear teeth all over inside the diff on the way to work one day.