SPOILER if you read on!!!
Anyway, by now you all should know Michelle is a double crossing low life so and so.
So let's get rid of her before that part of the story!
RPG's at her house don't work (I tried already), her windows are bullet proof, RPG proof, hell Nuclear bomb proof, so what else?
Come up with your ideas here..
Here's a few of mine:
When you are walking down the street with her, just punch her to death! Sure that is simple so..
Get fast car/bike, drive fast to end of pier and jump out at the last minute, and SPLASH