0.5 pitch BGA. Reballing the chip or the board?

[Buriedcode]

I plan on removing a memory chip from a phone and mounting it on an adapter board.  Without a preheater and decent microscope I can't see me having any hope of soldering the chip onto another phone's doner board, but the adapter board I bought has a footprint for it and nothing else - plenty of space around it and not much ground plane to suck away heat from the hotair.

This adapter board already has balls on the pads that *look* pretty neat and level.  So my question is, can I just remove the bumps from the chip, using wick to create a clean flat surface, brush with flux and solder onto the new board?  Effectively having solder balls on the PCB rather than the chip. As long as the boards balls are even I can't see this being a problem - but I'm not overly experienced with BGA, having only done a few before and only at 0.8mm pitch.

My only worry is, I don't know what alloy these PCB solder balls are, so I was wondering if I should just remove those and add my own with a stencil and solder paste (and leaded solder paste just to make life a bit easier).

[frogblender]

@Buriedcode... did you attempt this?  Transplanting a 0.5mm BGA does not sound like fun.   Curious how it went...