You will fill out Part 1 on page 2 of the amended return. This is for an increase or decrease in the number of exemptions. Your correct # XXXXX be one less than original. On page 1, you will refigure all the amounts due to the change--Taxable income, tax, possibly credits should change.
Under Explanation of changes, list her name and social security number with "Removal of Dependent" You also need to explain the changes for each line on page 1 that shows a change. If any forms or schedules have changed as a result of removing your daughter, such as Schedule EIC, Form 8812, etc. These new forms will need to be submitted as well.
Here is a link to the instructions for IRS 1040X. You should file ASAP and pay any resulting tax due: