Well, if you have the MIB2 unit, then if not already set up, a software upgrade will enable Carplay (and Android Auto) via a wired connection.
if you want a wireless connection there are a number of different USB plugin dongles which can enable that function.
Getting a touchscreen to replace the pop up screen is more challenging and usually involves replacing the screen with a complete Android headunit, which interfaces with the existing MMI unit.
See my thread on this
here
John.