The first thing you must do is make sure the domain name is not locked, or that would prevent it from being transferred out of the current registry. Begin by clicking on the Customer Login button at the top of the page. Enter your 1and1.com account username and password in the boxes on the log-in screen. Now click on the login button. You are now logged in to your 1and1.com account. Click on Manage Domains on the left hand side. This takes you to the Domain Overview page. Go to Transfers from the menu in the middle of the page. On the next page, Click Show next to "Lock/Unlock Domains". Select the domain you wish to manage from the list, and click Next. On the next page, Domain Locks, select the radio button in front of Unlock, and click OK. The next screen will let you know the action was successful. The lock has now been removed from the domain name, so it can now be transferred to another domain registry.
There are several other things that need to be done while you are logged in to your account. You should verify that your Contact Info is correct and up-to-date both at the current registry and the Who-Is. You also should obtain, most likely by email, what is called the EPP code, the Authorization Code, or the KEY Code, or it may be called a different name. It is the authorization code that allows the registries to permit the transfer of your domain name. This code needs to be given to your new domain registrar to begin the transfer process. When finished, click the Logout link, in the right hand corner.