Okay. I've done this several times.
Open Forms up, top right hand side in the blue
On the left side you'll see all your "Forms in My Return"
Search for the one you want to take out and click on it so it highlights in blue
Go to the top where it says "Forms"
You'll find a delete for the form you've highlighted.
Press delete and that form is gone.
This is a good time to check over your return to see if there are any other mistakes or double entries you might have made.
Just be careful not to delete anything that you might need or you'll have to input the info all over again.