||The download is an .rbz file that can be installed from inside Sketchup 8m1 or higher.
Go to Window>Preferences (Sketchup>Preferences on Mac) >Extensions>Install Extension... then browse to where you saved the .rbz download and follow the on-screen prompts.
The next time you start Sketchup, you will be asked for your email address. Enter the address you have used or intend to use for purchases.
Sketchup will continue to load, and you will have the Smustard toolbar visible. There are 2 buttons: one for the smustard.com main page, and one to track your purchases on mySmustard.
If you make a purchase but you don't get the email download link (usually due to spam filters blocking our emails), you can use this button to check your purchases. New purchases will have a download link available once you are redirected back to Smustard from the checkout page.
If you need to change the saved email address, open the Ruby Console (Window>Ruby console) and type
Smustard::ToolbarInit.changeEmail without the quotes, then press . You will be prompted to re-enter your email address.