Close MS Outlook
When you click on a link your web browser will ask to either download or run the setup.exe file. Either option is fine, but if you download it you will need to find the file in order to run it later.
Microsoft's installer will ask you if you're sure you'd like to install the TeamDirection Outlook Basecamp Integration. If you would like to install it, then click 'Install'.
If all goes well then the installation should complete with this dialog:
Restart MS Outlook. You should see the 'Add Ins' tab in the ribbon. When you click on this tab, you should see TOBI's icons:
If you would like to remove TOBI, go to your control panel and remove the program just like any other application.