Language / Help! can someone help me change polish to english for firefox?! [9]

hi guys .. I would really really apprecaite someones help..

On the laptop I use there is firefox, however its in polish, abd i know verrrrry little unfortunately! i need to change it to english and all the forums tell me how to do it ,b ut they tell what buttons to click in english so icant tell which to do in polish!!

I am not the administraot so i cannot dowload anything i just want to change the settings in existing polish mozilla firefox!!
please help I cant do anything!!