Prior to the uninstallation of portatour® it is necessary to remove all assignments of users to portatour®-Permission Sets in your Organization. Navigate to Setup / Administer / Manage Users / Users. Click on the Username of the User who installed portatour®. In the Permission Set Assignments – Section remove all portatour® Permission Sets.
Repeat it for all users who you activated for portatour®.
Navigate to Setup / Build / Installed packages and click on Uninstall next to portatour®. Confirm the uninstallation.