First of all, just in case you are asking What are nameservers? Now that is out of the way.
To make DNS changes at Dotster.com, log in to your account and follow this guide.
1. Select the domain to change and click ‘Update Name Servers’
2. Enter the primary name server and click ‘Add’
3. Dotster will automatically fill in the secondary name server field, check that the details are correct, amend if necessary, and then click ‘Add’
4. Enter your email address to receive confirmation of the changes and click ‘Continue’
Note: You need to enter a minimum of 2 nameservers.
Warning: Do not enter your IP address; this will cause problems.
Remember, it can take up to 72 hours for the changes to take effect.