How do you remove lines on a form?

I scanned in a form using Acrobat 11 Pro on Windows and would like to remove some horizontal rather widely spaced black lines that were ment to be written on. I can find no way to do it yet. I would like to have the area clear of lines so text can be entered in the area at a different line spacing for the area originally designed to be filled in by hand.

I tried various things but it seems like the program doesn't recognize the lines as images or objects.

Thanks