How do I replace the spring on a robo coupe? - Robot Coupe R2U Ultra Food Processor

Are you referring to the spring in the cutter bowl? You will need to remove the retaining nut. The spring will then come out. the part number for the spring is R1776. Whole assembly part # R242.
Are you referring to the spring in the on and off switch? You will have to replace the switch. If you call Heritage Food Service Equipment, they will be able to fax you a parts break down so that you will know what part is needed. They can most of the time tell you how to replace the parts also. You can contact them at 1-800-253-0200.