No laughing now...Lego in my Play 5!!! HELP

Ok, I thought I was safe...
My eleven year old son knows not too much around with the Sonos kit, he loves using the app on his phone to play whatever tunes he likes...my daughter however , is different!!!

She thought it would be a great idea to turn one of my Play 5's into her new bankie! She discovered the opening in the back of it and thought wow how many coins and Lego can I hide in here...ARRRGGGHHHHHH!!!!

So...Is there an easy (ish) way to get the Lego back out? Fortunately the unit is out of warranty so I have no qualms opening it up...but obviously do NOT want to damage it in the process...so on that note, I await your useful suggestions/advice.

Thanks in advance,

LocheeLad