To amend the Desktop program. Start by opening your return as usual. Go up to File-Open.
If you don't see a button for Need to Amend a Filed Return? on your home screen then you can get to it here. Go to:
Federal Taxes -or- Personal (for H&B)
Other Tax Situations
last section, Other Tax Forms
Amend A Return - Click the Start or Update button
How did you file the original return? Did you efile or mail it? You first might have to tell the program it was filed. If you efiled you have to check the filing status inside the program. Open your return and go up to menu item
File > Electronic Filing > Check Electronic Filing Status
Then save your return with the status. Go to File-Save. Oh and be sure to save your original return with another name so the amended return doesn't overwrite it and you can start over if it gets messed up.
