Before updating the desired tools, you need to select them in the list. You can manually tick the check boxes next to the tools you want to update.
Once you have selected the tools you want to update, press Update selected, in the left pane. You can press Update and run selected instead, in which case Tech Tool Store will run each tool after updating it.
Upon confirmation, the update process will begin. You can cancel updating a single tool by pressing the Cancel tool button, or cancel the whole update process, by pressing the Cancel All button. Both cancel actions need confirmation.
When the update process is complete, Tech Tool Store will return to its normal interface.