From Real Social Dynamics Wiki
Begin by speaking to a Dwarf on either side of White Wolf Mountain.
 What You Need
A regular Fishing Rod, about 120gp, about 10-20 Red Vine Worms, a clove of Garlic and a Spade.
Scroll down to the end of the guide to find a 'Fast Quest Walkthrough'.
 Getting Started
First log in youe runescape accounts then make sure that you have your Fishing Rod ready and speak to either of the 2 Dwarves located on each side of White Wolf Mountain. One is located just southwest of the Heroes' Guild in Taverley, and another can be found northeast of Catherby. Ask him to be friends, and he says that he will accept your offer if you can prove that you are really a friend.
He talks about the Hemenster Fishing Contest and that the Dwarves were going to enter, but they don't really make good fishermen. Tell him that you are quite the fisherman, and he will give you a Fishing Contest Pass.
 Getting Ready
First, you need some Garlic, which you can find in a house located just southwest of the bank in Seers' Village. Now go over to Hemenster and ask Grandpa Jack for some advice. He will tell you that you should fish near the pipes and use some Red Vine Worms, which are found in McGrubbor's Wood.
Go north to McGrubbor's Wood and enter through a loose board along the north side. Search the Red Vines on the north side of the wood. I would suggest to get quite a few of the worms-- about 20 just to be safe, in case you don't do it correctly.
 The Contest
Now head to the Fishing Contest area near the Ranging Guild and use your Garlic with the pipes near the fishing spot. Start trying to fish and then pay the 5gp entrance fee. After the Sinister Stranger smells the Garlic, he'll move to a different spot, and you'll get the area over by the pipes so fish there and you should catch a Raw Giant Carp.
You will then be given the Hemenster Fishing Trophy, which you can take back to one of the Dwarves to gain your reward.
Access to the Dwarven Pass under White Wolf Mountain,it will save you a lot of time and runescape gold on power leveling. 2,437 Fishing experience 1 Quest Point