Hello all. I have a galaxy s2 phone and the buttons for the volume are broken. i tried to install an other software the cyanogen. i didnt do correctly the steps so the phone now has stuck on the start screen with a yellow triangle under the sumsung logo. What can i do so as to delete evrything and install android again? i tried using adb but i had several problems with that. Please describe the steps specificly because i am not a pro. thanks in advance.