Of course. There's no procedure: just log in from a different computer, click on on-line chess, and make your moves. Don't forget to log off afterwards if you're at a public location (e.g. internet cafe). As long as you make your moves within the 3 days/move (or other) limit, chess.com doesn't care from which computer they were made. All games are stored on chess.com servers, not on your computer.
I am new to online chess. Can I start a game and continue it on another computer if I go away. ie. can I just log in and what is the exact procedure?