Cleaning Mayflash Arcade stick perspex?

Hi guys,

I'm starting to mod my 2nd stick. My first I built with an XBOX 360 controller and made a wooden housing. This time I thought I'd save some time and mod a pre built stick so I've bought a Mayflash Arcade Fighting Stick (This one)

I've taken the perspex plate off which has the pre printed artwork on the underside. Can anyone recommend the best way to remove this? I'd like to use my own artwork which I'll place underneath.

Thanks in advance.