I saw that item on ebay. It looks like you could probably MAKE it fit. But I'd look for one from a crown or speed that just screws on. I think the XL back would need to be attached to your current springback, and it would take a bit of cutting and shaping to make it work.
It would be more difficult to use the XL back, as the body styles are different, your best bet would be to find a crown back, which should pretty much just replace your current crown back, pretty straight forward transplant, but you might be able to buy another crown with the graflok for as much as you would pay for the back alone.
If we're talking about adapting a 4x5 Graflok back made for an XL, don't do anything but buy it, then hunt down an XL: most folks think they never existed but they do, and you CAN shoot 4x5 ( well, 3x4 ) on an XL.
If you talking about ... well, if you're thinking about 'upgrading' a springback , unless you're shooting Polaroid, why bother ?
No go. The XL back attaches to the XL with four large pins that mate with holes in the body. The 2x3 Graphics' backs attach to the body with four little screws that go into little clips. Not wood screws, as looks likely. And guess why I know it can't be done.