It all started off canon compliant.
Sybill Trelawney gave a prophecy to Albus P. W. B. Dumbledore, Severus Snape overheard, and reported to Lord Voldemort. The prophecy stayed the same as it was in canon, of course. Lord Voldemort went after the prophecy child, and Peter Pettigrew revealed the secret to him.
In this version, however, Neville Longbottom was never counted as a prophecy child. Why? Because he was born a day too early, not because he was a half blood. Honestly, Dumbledore, you idiot.
Voldemort arrived at Godric's Hollow one Halloween night, and the only difference here is that Lily and James have their wands (because they aren't idiots). When James tells Lily to run, that he'll hold him off, he actually has a bit more power, leaving Lily to run.
When a killing curse clips James Potter on the leg, he falls, arms outstretched, dead.
Voldemort steps over his body like the sick freak he is, heading up the stairs towards the nursery. Lily Potter refuses to step aside, and Lord Voldemort throws a killing curse at her - but wait.
A killing curse can be deflected by a non magical shield, such as a wall, you can't Avada Kedavra someone through a wall.
And Lily Potter, with that brilliant brain of hers, conjures a chunk of metal, which deflects the killing curse back at Voldemort, who merely conjures his own. The twice rebounded killing curse flies at little Harry, and BAM, he collapses. Lily Potter forces Voldemort to kill her because of the loss of her son, and he complies.
The second poor Lily crumpled to the ground, the child gasped for breath, revived by his mother's love. Voldemort watches with idle curiousity, only to see a the wand movement he was so familiar with carve itself into his forehead, and green light fly from it. Then he only felt pain.