To renew your membership, Log In at the upper right, using the email address at which you receive email from PS SIGCHI. (If you've forgotten your password, click the Forgot Password link.)
Once logged in, click the View Profile link at the upper right. On your Profile page, you can click the Renewal button to renew your membership. If you have enabled automatic renewals through your PayPal account, you will see a message to this effect instead of the Renewal button.