For upgrading firmware, i always suggest a wired connection
To connect to the mount, you will need a USB to serial adapter ( preferably with an FTDI chipset in it )
and a "507" cable. You can buy these from Meade as an adapter and cable set, ( very expensive )
you can get a generic converter and make your own 507 cable,
or you can now buy 3rd party converter + cable units that do the lot in one cable.
( The latter are neater but the converter cant be used for other purposes )
If you truly want to go Wifi or BT, there are also several options out there now
Meade have their own battery powered units ( Stella )
but there are other 3rd part ones as well, i i recently saw these
but there are others if you look
As to firmware, you can download and instal the best working firmware plus its patches from the StarPatch site
Much more robust than Meades ASU and well tested firmware.