If you delete a computer from one account and disable/enable LogMeIn on that computer, the program will give a pop-up saying it can't be attached to an account. You will then be instructed to open LogMeIn and re-attach it. Enter the desired account email address, and you should be golden.
Please note that this will only transfer the computer itself. If there is a paid license involved, it will remain on the original account.
Jeremy Soltys
LogMeIn Customer Support Rep