I'll show you how to modify the transactions, odyessey2008.

You can simply undo the transaction by selecting the Type link.

Here are the steps:

1. Go to Transactions on the left panel.
2. Find the transactions you want to change.
3. Click the Personal link under the Type column.
4. Select the Business type and choose the correct category.

Here's a sample screenshot for a visual guide: 

Please feel free to read this article for more information: Categorize transactions in QuickBooks Self-Employed.

I'll be right here if you have more questions about categorizing transactions in QuickBooks Self-Employed. Just add a reply below and I'll get back to you as soon as I can. Take care and stay safe.