my mates done it. see www.zetecinside.com for a 10 step guide with all the reletive info & pics
ive bought a mk1 fez to do the same but now my brand new cosworth is complete, i dont know if i will get round to it.
i bought a cheap fez rs1800 for the conversion but just sold it for good money.
if i come across a 50 quid mondeo i will probably do it at some point over the winter.

its a £700 job at my local rs fettling station!!!