Whatever method you choose the lathe basically has to be lifted. Either onto the wheels/roller/rails or off them using jack up legs as its normal support.
If the lathe is already in the corner the devilish detail is how to get it out so you can apply your chosen method to that corner.
In my case I had enough clearance between the tailstock end of the lathe cabinet to tilt the 1024 enough to slide some 1/4" or 1/2" diameter rods underneath aligned across the bed. I used a farm jack, the click-click-click climb up a vertical rail thing, to raise the headstock end. As I recall it I got a rod to within about a foot of the tailstock end. By using the rods as combination rollers and rails I got it out far enough to work on that back corner.
I suspect that if you choose to use a system like mine it will be possible to tilt a Boxford on its cabinet far enough that one roller frame will get far enough down to the tailstock end to achieve balance with the headstock end supported on the other one.
Not a method I'd use more than once tho'. I've done similar in another case and it was all a bit precarious untill dropped back onto the roller frames.
If you decide to follow Bills suggestion with jack up castors make sure the jacking system is nice and solid.
I have a large set with the wheels welded to a square vertical tube which runs inside another tube fixed to the thing to be moved. A big screw with a tommy bar head moves it up and down. Wheels are 6" diameter, load capcity is high, pushing a ton each according to the specification and they cost the firm a fair bit of money. In practice the relatively loose fit of the tube in a tube means they don't actually work very well at the moving thing. I hauled them out of the scrap bin thinking they couldn't be That bad. With a ton of Pratt & Whitney sat on 8 I found they were worse actually! The slop in the tubes meant they really didn't want to swing around as castors should. Turning meant crowbarring up to take the weight of each castor in succession and lining them up by hand!
Clive