The new system has been updated that integrates the second level .com.pk domains under the first level name.pk accounts.
Now you can modify your legacy domain online from main page of PKNIC website under the head "Manage Legacy Domain Names" using domain authorization code.
Please note that the domains registered using text based domain registration forms (email template) are categorized as legacy domains.
It is suggested to import your legacy domain to .pk account to take advantage of the account facilities. Once a domain is moved to an online account, the Authorization code will no longer valid and will not be required for any modification.