Write and submit a formal letter (not email) to your Undergrad Advisor requesting to postpone your studies in Systems Design. Include your reasons for same and the Academic/Work Term Sequence Change form.
If your request is reasonable, the Undergrad Advisor will determine if there will be space in the future class that you wish to join and will notify you of his/her decision.
If you are looking to do a non degree term then refer to registration information under the link Non Degree Term. If you will take courses at another university then refer to information under Letter of Permission.