Editing a transaction is easy. Just click on a transaction to expand it, and edit it as you like. Linked transactions allow you to edit the description and category, and manual transactions let you edit the date and amount of the transaction, along with whether it’s an income or spending transaction.
You can also Bulk Categorize transactions you wish to categorize all the same. Simply click on and check off the boxes on the left of the transactions you wish to categorize all the same. Next, select the proper category from the "Categorize as" drop-list on the highlighted bar that appears now at the top of the transactions list. Lastly, click on the Apply button and all the selected transactions will now be categorized the same with whatever your selection was.