No standard solutions found till now.
Helge suggests circumlocution "ahya mir (aiqua)" and widely uses it in his NQNT project. 

Thanks.

I guess the idea of using mir owes to the form mirroanwi [< *mi(dă)–sraw–] *"incarnati" (where the "into flesh" might be understood in either illative or translative manner).

Let's not forget virya- (a reference to AS weorþan?) "change, alter(nate)" from PE17:189.

Too bad there doesn't seem to be any indication as to which case/preposition the result ("changed into") would require with virya- or ahya-.