How Do I Re-categorize expenses from last year?

I am new to QB online and apparantly mis-categorized a lot of my expenses to the point that when i did my tax report, most of my stuff bought for resale did not get deducted, so its showing way to much profit. Ive gone in and re-catergorized many of them, but it's not changing on the tax report. Surely there is a way to change it. 

Help Please!