If you want to add or delete personal or dependent exemptions from your tax return:
Click on the personal info tab and click edit next to name of the person you want to remove or you can click add dependent.
If you want to change the number of exemptions you claim throughout the year, then you'll need to fill out a new form W-4 and give it to your employer. You can use the Turbo Tax W-4 Withholding Calculator at the link below.
https://turbotax.intuit.com/tax-tools/calculators/w4/