Blue background means your MK nav unit is not working (it doesn't render the menus and it reverts to the blue-ish theme). And yeah, since the MK is gone, there is no nav capability either.

The disk can be pulled out with a needle through the tiny hole near the eject button. Similar to any other CD/DVD/etc drives. If the needle hole is missing, you will have to take the front plastic face off.

Unless its bricked, disconnect the two brackets behind the MK (maroon and blue) and reconnect them back on.