1st: sign in to the account with the rank you want. (must have gold to work)
2nd: go into a versus on standard, then pick any game type.
3rd: start searching and as soon as the black marcus screen comes up sign out and sign into the account you want to have the rank of the first one. (as fast as you can)
4th: then it will say u lost connection and hit (A) button or ok
5th: change your multiplayer stuff to what you want.
6th: (one of the most important steps) play a full versus match to make it stick.
7th: enjoy you new rank and stuff.

hope this helps you bro.