Your copy of MSP should download the update automatically. However, you can check for updates by going to the Help menu and selecting "Check For Updates Now..."
Mac: If you are getting an error Code 5 when attempting to install the update, this indicates you either need to: a) log in to your computer as an Administrator first, then install the update or b) close MSP and hit “Try Again.”
PC: If you are being asked for your Username and password, this is your computer asking for permission to install a new program. Contact your IT department if you do not have this information.