This is for the German Version of Saints Row 2 (SAINTS ROW 2 BRD), which is not uncut.. some of the activities and story parts are missing! so you may check the other solutions writen for the original as well..
Due to the fact that there are no finishing moves in the German version of this game this one isn't easy, but isn't to hard either..
Have enough food and collect the food that drops into the arena. Try to run in circles (inside the arena) and use everything possible to knock em down.. avoid fighting against more than one at a time and use a lot LT (it's faster than RT).. Don't waste your time on knocked down enemys, instead execute some combos on the others..