If you have not filed, you can simply remove the W-2 then re-enter your 1099 SSA.  Here are the steps (online):

• Sign into your account, select Take me to my return
• To your left, select Tax Tools, click on the drop-down arrow
• Select Tools
• Under Other helpful links, choose Delete a form
• Scroll down the list to locate the Form W-2, select Delete and Continue with My Return

To enter SSA-1099 information, here are the steps:

• To your right upper corner, in the search box, type in "ssa 1099" and Enter
• Select Jump to ssa 1099
• Follow prompts