How do I clear transmission warning light off Vauxhall Astra 2004?

Transmission warning light came on. I had the vehicle repaired but the light is still on. Is there any way I can turn it off or does it have to be taken back to the garage?|||It needs reset by computer diagnostic kit. The mechanics should have done that after they had finished. It takes two minutes - but you will have to nip it back in to the garage, I'm afraid.|||You need to take the car down to the dealer and get it re-set.|||i would take it back to the garage that done the work cos i would worry that the work had not been carried out , but that's just me that's the luck i get ;)|||hit it with a hammer lol|||piece of electrical tape|||Sell it|||take the negative lead of the battery, wait 30 seconds then put it back on. (make sure you have the code for the stereo)