Its basic hooking
void (*old_hitbox)(void* player, void* vec);
void new_hitbox(void* player, void* vec){
if([switches isSwitchOn:@"Head Hit"]) {
(*(Vector3 *)((uint64_t)vec + 0x24)).x += 9999.0f;
}
old_hitbox(player, config);
}
setup() {
HOOK(0x1234567, new_hitbox, old_hitbox);
}