Sign in to your Trimble account with the e-mail address and password you used when you purchased the license and the download links should be presented in the link I provided.
Unless you have managed to get ‘Product Access’ in the Members section, you won’t be able to get to the download link in the UI. Even than it is not that obvious, though.
In the My products section on the left, click on ‘View Included Apps’ in SketchUp Pro, Than on Downloads: