You'll need to revisit the job-related expenses section to change the occupation for which you incurred expenses.

• Open (continue) your return in TurboTax Online. (If your return isn't open, you'll need to sign in and click Take me to my return.)
• Click My Account (top right of your screen).
• Select Tools.
• In the pop-up window, select Topic Search.
• In the search bar, type 2106.
• In the results box, highlight 2106, then click GO.
• You'll land on the Job-Related Expenses Summary. Click Edit next to the entry you wish to change. (Click the first screenshot below for reference.)
• This opens Tell us about the occupation you have expenses for. (Click the second screenshot below.) Edit the occupation and click Continue.
• Continue advancing through the tax interview. When you are finished with this section, you'll see the Job-Related Expenses Summary again, with the occupation changed. (Click the third screenshot below for reference.) 

Note: If using the TurboTax CD/Download software, you'll use the Find function (instead of "My Account") to search for the topic.