De-restriction of your Aprilia is a complicated process that can only be accomplished by a dealer equipped with Aprilia's AXONE computer software. De-restriction includes removing airbox and exhaust flow restrictors, removing a throttle stop which limits throttle opening, and remapping/reprogramming the electronic fuel injection ECU (electronic control unit). The remapping process includes reprogramming the ECU and requires that the electronic throttle position sensor (TPS) be recalibrated for minimum and maximum throttle position. Re-mapping requires a special cable to connect the ECU to the AXONE computer. The entire procedure takes several hours and costs about $350 USD at most dealers.
Parts removed upon de-restriction: two exhaust flow restrictor cones (solid cones) and the throttle stop which prevents full-throttle movement.
These spark arrestor cones are not part of de-restriction. Some feel that removing them increases flow, but it may not be a good idea or legal where you ride.