how to extract the most money here?

I searched and searched through my hand history but I couldn't seem to find this so you'll have to bear with me here. This is from a $25NL party poker table:

I'm dealt pocket 8's, a couple people fold up to me, I limp in, 2 others limp in, and one other guy makes a little 2xBB raise, everyone calls.
flop = K8J
i make a 3xBB bet hoping someone at least got a pair, everyone folds but one who calls
turn = 8, I check, he checks
river = rag, he bets pretty big, like $12 I think, I push, he folds

is there a better way I could've made more money having the absolute nuts?

Keep betting when you've already started... At that level, you're expected to slowplay every big holding, so do exactly the opposite and represent a weaker holding like Kx or Jx.

if he bet that big, just minraise the river. This is probably the only time you will ever hear me say that.

I agree about min raising the river here. However i do think you should have min raised the turn, if he had Kx or maybe Jx he may have raised you thinking he smelled a rat. I dont know how he would have reacted to your call however, i assume you checked it to him on the river when he bet big. He may have just checked behind. Great hand, sorry but im in the beginer section for a reason!!!! wish i had better advicd

bet the flop.
Look as though your thinking then bet the turn a little smaller suggesting your scared then when he calls check it to him onthe river. If he checks behind fine, if he bets you go over the top for whateva you think he called. As said, if you have the stone cold nuts its expected you'll slow playthem not bet them

Since you made a 3xBB raise on the flop, on the turn I would have made a smaller raise...maybe 2.5xBB and hope he smells weakness.