The following are the steps you will need to perform in order to transfer away from Dotster:
STEP 1. UNLOCK YOUR DOMAIN
Login to Domain.com control panel, click on DomainCentral
Select your domain and click on Security
Click on Unlock Domain
STEP 2. OBTAIN THE EPP/AUTH CODE
Click on the Transfers menu item
Click on the Send Auth-Info Code button.
Once you have recieved the auth code...
STEP 3. INITIATE THE TRANSFER ON ZONEEDIT
Follow the prompts. You will recieve an email from ZoneEdit/easyDNS which contains a link you should follow where you will confirm the transfer request.
Once you approve the transfer, it will complete in 5 to 7 days. If you have the ability to explicitly confirm the transfer on Domain.com it can be done faster.