Transferring ownership of your domain is very simple and can be done in the domain manager.
1) Log into the domain manager under the domain you wish to transfer.
2) Click on the 'Profile' link.
3) Click on the 'Change Ownership of Domain' link
4) Enter the new username, password, and confirm the password. Leave the 'Move to existing profile' box unchecked and the text area 'Previously registered domain' blank.
5) Click 'Change Owner'.
6) You will then be managing the domain in a new, separate profile. You can then change the information to the new owners or give them the username/password and have them change it.