Default [Q] Samsung Galaxy S2 Epic 4G Touch 4.0.4 Help

i am kinda new to this website and anyways,i have a friend that wanted me to root his phone (Samsung Galaxy s2 epic 4g touch running 4.0.4 model SPH-D710) And i though his phone was just an s2,because he didn't tell me about the epic 4g touch part,and so i downloaded the wrong tar file and flashed his phone with the wrong file,so now when i try to boot it up it just shows samsung galaxy s2 with a yellow triangle with and exclamation mark and then it turns black and never turns on.SO i wanted to root it and now what do i do,i want to unroot it now with it working.Please help my friend will kill me if it ain't working.