Can I remove a 1099 income entry after saving it (I've accidentally entered it twice)? If so, to where should I navigate to do so?

There are about 20 different kinds of 1099's.  What kind are you referring to?

I think you should be able to locate the items by switching on the forms category. You should be able to see all your mistakes highlighted with a red exclamation point. At the bottom of the page there is a delete form tab you can use, but first make sure you have located the problems you want removed from the file...or, you can do what I did by starting the file over and reenter all your data over.