This will be pretty basically written out. If you need further help, please inform me via PM.
First off, make sure your wow client has WOTLK and you have hamachi on your computer. Then set your hamachi server to RP Private server, the password is Yoshi(yes, its capatalized with the Y). Then, go into your realmlist and make it look exactly like this....
set realmlist 5.54.110.120
set patchlist us.version.worldofwarcraft.com
set realmlistbn ""
set portal us
Alright, so now your computer will be able to go onto the private server. Anything missing? Oh right, an account.
You will need to contact Zeromaster3 on his AIM, Zeromaster2006 and he will set one up. Let him know what you want the password and username to be. It will take about 10 minutes for you to get on.
So like I said before, contact me via PM if you need further help...