Oysi Frames posted 2 videos to help you modify your souplates along with a blueprint to be able to ride 72 mm wheels.
Oysi Inline Skating Chassis - Soul Plate Modification Template
Modify your soul plate for use with the Oysi Inline Skating Chassis. Download the Soul Plate Modification Template here.
Oysi Soul Plate Modification (No Tools)
How to modify your soul plate to accept 72mm when using the Oysi Inline Skating Chassis.