Complex sentence: McAlester, in a sacrificial effort to distract the last of the three sharks, allows it to kill her, her sacrifice luring the shark into a position where Preacher and Blake can shoot it and attach it to the battery, blowing the shark to pieces.
Split into simpler sentences: McAlester, in a sacrificial effort to distract the last of the three sharks, allows it to kill her. Her sacrifice lures the shark into a position where Preacher and Blake can shoot it and attach it to the battery, blowing the shark to pieces.