Put it in the middle of the road and place a ramp infront of it, then get your motorcycle and take a long run so you get to like 80mph and jump right on top of it.
1. Stand in a field (or a small playground)
2. Grab all of the wires
3. Wildy spin it around over your head
4. Repeat step 3 until g25 dislocates itself and hits someone.
Normally they don't actually wait for you to prove you've destroyed it, they used to ask for the end of the cable in the post, but I got another wheel despite not sending them anything. The shifter and probably the pedals are bound to sell on ebay, even better if you don't have to cut any cables so someone without a G25 already can connect them and use another wheel.
yeah they've started being stupid and asking you to destroy it, it happened with me and my MX Revolution, i just told them i wasnt prepared to destroy it and if they werent going to replace it then i would take my custom elsewhere and they replaced it straight away.