Requirments:
An account with 1600 - 4000 MS points
Information of the account with points on
Information on the account you want to transfer it to

What you do:
Step 1:
Call MS (]1800 - 4MY - XBOX), and get transferred to the Live department.

Step 2:
Once you get through, follow their instructions and give them all legit info. Tell the rep that you accidentally put the points on the wrong account and you need to get it switched.

Step 3:
They should tell you that they will evaluate the case and you will be receiving a phone call soon with the results.