If a domain registered with Sherweb, client could change the nameservers from account manager itself using the below steps.
1.Login to account manager of the desired account.
2.Click on domains and Manage domains near to the desired domain name.
3. Click on Manage domain locking.
4.Disable the locking and click on Apply
5. Repeat step 2.
6. Click on Manage Nameservers.
7. Add the new nameservers and click on Apply.
8.Repeat step 2 and 3.
9. Enable domain locking and click on Apply.