BUT there are so many fantastic things you can do with a Dremel. 
Just kidding!
Mine is collecting dust in the cellar and I really would not dare to take it near my smartphone. Most likely I would find out the fastest and most sure way to destroy a smartphone (aside from the “will it blend” -marketing-solution).
At least it would take a work-station besides the Dremel, as - at least my - hands are not steady enough.
I would try another solution - most likely glue - as well
One just has to be careful not to - accidentally - glue the screw to the board/module. 
I keep my fingers crossed for you and would love to read a success-story sometime soon. 