I need help losing weight for my sister's wedding... its in a month and a half... plz help :)?

hi, i am 20 yrs old, 5.6 in height and weight 60 kgs. i need to be down to atleast 55kgs before my sisters wedding, which is at the end of oct. can someone plz recommend a sort of exercise plan or something? crash diets are absolutely useless for me since i am a full time student and i eat when i study so.... i would be grateful for any sort of help. plz plz plz plz plz help :) thanks!