Defeating Lord Sadler and escaping the island with Ashley! Resident Evil 4 Final Chapter

It's been a long time in the making, but now Leon and Ashley are free of the plaga parasites it's time to finish off Sadler for good and escape the island! *EDIT since completing the main game, i've played through Seperate Ways and Assignment Ada. I'm really struggling on mercenaries mode though due to the mad chainsaw ganados! My playthroughs are going great, racking up serious killstreaks and getting tons of free time BUT THEN some maniac comes along with a chainsaw out of nowhere and 1-shots me! GAH!! /rant over lol*