Sadly, the answer to both is 'you can't'
VM refuse to supply 4G to their domestic customers, (business users are catered for though!!)
And the chances of that ever changing are small. (look at some of the old posts on here, going back a couple of years at least)
They just cannot be bothered to offer what all others are now providing. Sadly, if you want 4G then you will need to look at another carrier, because it isn't going to happen on VM.