How do you defeat megatron on transformers autobots

hit megatron in back 4 or 5 times ok.he drops the allspark you quickly pick it up and hit it on him not throw it in him only hit.you die cause of the allspark then its prime vs megatron!the secret is to keep shooting him and when he shoots you jump.if you get hit and your losing life run and deafeat all the other drones!!!! hope this helped!!!!!!!!! sincerly hcd