After you file

Those are just common items to amend.  You can just go to where you need to as normal.

Go to Business tab- then Continue

Business Income and Expenses - Click the Start or Update button

 

Then click EDIT by the business name and the next screen should be a list of  topics,

Business Profile, Income, Inventory/Cost of Goods Sold, Expenses, Assets, and Final Details last.

 

Under Business Expenses - click Start or Update by Home office expense