A bit late since the move should meanwhile be over, but still. There is absolutely no way you could, or should do this, for too many reasons to even know where to start.
But of course, there's theory and there's practice. In reality, showing good will but having a little "accident" early on that day and calling in sick for the remainder might be the smartest thing to do. Unluckily, with that sprained ankle, you can do no lifting.
Because, you know, the person who complains first about very reasonable concerns is the first to be fired. That's life. So, although you are absolutely entitled to refuse this crazy endeavor, it will come down onto you negatively if you are the trouble man (even moreso as you seem to have what looks like a "typical US-style management"). If nothing else, you get a negative rating at the end of the FY. Nobody likes the trouble man. We want solutions, not complaints. Pussy.
Moving typical "machinery" on their typical little wheels (at that weight, probably cast metal) works -- if the ground is even. Otherwise, no way, forget it. Pitted road? Got suicide tendencies? The possibly best thing that can happen is one of the wheels getting stuck in a pit and the machine becoming unmovable thereafter. That's the absolutely best thing that can happen (and something much more desastrous is more likely).
The idea of moving something of any considerable weight, let alone 450kg, up a 45° pathway for half a block on pitted ground as pointed out in an explanatory comment is just outright hilarious. Even assuming that this may work is unreal. Try and walk 45° uphill for half a block with no weight.
Some of the steepest roads on the planet have an inclination of around 35%, which is a mere 17-18°. Usually, there's warning signs for as little as 10% already (for good reason!). So you are going to push half a ton of weight on cast wheels (presumably?) uphill on a path three times as steep. You need not be a rocket scientist to see that this will either not work at all, or end badly. Makes you wonder what forklifts were invented for.
There is this thing called due diligence. Whatever your boss tells you, you still have due diligence or you get in trouble when something happens (note the wording when, not if). In a situation like this, due diligence can be assumed not to be present, so when something happens, your indemnity insurance won't pay. And of course, the blame (from management, for the lost machine) will be on the person/people having touched the machine last. So, don't be that person, don't touch it.
What could happen? I am not even going to start about this thing rolling downhill or toppling and crushing someone underneath. It's enough if someone gets his toes under one of the unforgiving wheels. I've seen people lose a couple of toes due to considerbly less heavy stuff rolling over their unprotected foot. You do wear metal-cap boots in your office, don't you... :)
Let's not think about getting yourself a hernia or a bad back either, lifting around crazy heavy stuff as an untrained office guy, without proper equipment. Nothing's gonna happen, right.
What's worst, you do not even need to get the weight on top of a part of your body to get serious harm. Once 450kg are moving, it's enough to have your hand in the wrong place (between machine and wall, or door). You cannot shout "stop" fast enough, and if you could, your co-workers couldn't stop the thing before your fingers are pulp.
Even if no body parts are in the way, you cannot shout "stop" fast enough before the rolling monster turns the entrance door to rubble. Or the photocopy machine, or whatever comes in its way. Who's going to pay?
Getting the machine onto the truck is actually a lot easier than you would think (I've done that, never having done it before). But it's still a needlessly dangerous thing, and do you really want to have the responsibility for whatever happens when that thing falls off, even without killing someone?
Anything but hiring professionals for such a thing is outright insane. Of course, there's no way you can tell that your manager, so there's the solution with that sprained ankle.