Hi,
Installing Opus on your new computer is the same as installing it on your old one.
Download the program and run the installer.
If you have lost your licence/certificate, log into the online licence manager or use the Lost Registration Retrieval page.
If you want to transfer your Opus configuration from the old machine to the new, see How to back-up or locate your Opus configuration.
I think those are the only things you might need to worry about, but if you have any other questions about moving Opus from one machine to the other, ask away.
Leo