1. Search for the domain as normal.

2. When you get to the checkout page fill out as normal but select "Add New Contact" under Domain Registration Information. 

3. Click on "Complete Order" and the page will reload with new space to enter Domain Registration Info. Here you need to enter the details for the person you are registering the domain name for.

Please bear in mind that the domain will still reside in your account and you will be the DomainDonkey contact for management and payment of the domain.