First of all, if you feel like spending the money, it is not a waste. There are many years of pleasure and agony ahead. But, it must be part of why you have taken up the pursuit. It is a participation 'sport'. If you screw up, you might be out $75 plus tax, but you'll be at least $100 smarter. So, plan and execute more, worry less.
It is just like doing a small juniper, though maybe a bit unwieldy - just do things like sawing off the bottom of the root 'ball' proportionate to what you've done before. Obviously you are not going to toss this up on your bench, so you'll be improvising in a big flat area like your driveway with bricks and 2x4 props/levers/slides or the like (you may be surprised at how light it is once you've removed part of the old soil mass). I suggest that you
also secure it with guys from some strong branches to eyes on the sides of your box. Then winds/accidents or simply moving it won't stress the roots (take these guys away once the substrate is populated with roots the end of next season or the year after).
At most, I think you might need another set of hands to just hold it in place while you do things that take both of yours = a willing wife or neighbor for a few minutes ought to be all that you need (personally, I wait until I cannot get out from under it to call for help

).
It might be your judgement that it would be better to put the box where it is going to be and carry your unpotted tree to it for potting 'on site' as opposed to potting it in the driveway and moving the whole works.
And enjoy a glass of your favorite beverage afterward!