In order to re-authenticate with Yesware, simply click the Yesware button and choose "Log Out." Restart Outlook and follow the steps to activate.
If you see "Purchase Yesware", please follow these steps to activate under the correct Yesware account:
1. Close your Outlook.
2. From your desktop press the Windows key on your keyboard + R.
3. Type in %appdata% into the dialogue box that appears.
4. Delete the following folder: C:\Users\<user>\AppData\Roaming\Yesware
5. Open Outlook and activate.