If you need to change your email after you have purchased your subscription and created your Trimble ID, you 'll need to follow these steps :
1) Contact us so that we can re-assign your license. Please include both the existing and new emails in your request so that we can switch your license to your new email. Please use our Help Center Support form : Submit a Request
2) Update your email in your SketchUp Australia Account (under Addresses > Billing Address and Account Details). See Manage SketchUp Australia Account Dashboard.
3) Update your email for your Trimble ID. See How do I change my Trimble ID email address?
Note : you'll need to sign in to your Trimble AMP to do this.