Step 1)  To Delete Accounts in GramDominator  you need to visit: Account--> Accounts Manager 

On this screen you will find 3 buttons :- Load Accounts, Add Single Account, Delete Accounts.

Step 2) Click on "Delete Accounts" 

To Delete Instagram Accounts you need to click on button "Delete Accounts". Once clicked a modal window will Popup and you can select whether you want to delete all accounts or you want to delete Non-working Accounts

Select From Delete Options and click on Delete.

Getting trouble indeleting accounts contact support.