With Studio One you get up to 5 activations at once. So If it's only your second computer, you would just install it and connect online, maybe need the serial number. If you need to remove an activation you can easily do that from inside your account Products > Software > Studio One - View More Details it should be listed just underneath your registration key, with how many activations you're using. In my case the icon says "3/5 Activations - Manage".