Impossible no matter how hard you try. Besides, the real things and replicas are too alien internally. Replica parts and real parts are not compatible or interchangeable, even on 'real steel' replicas. There is no concrete records of anyone who had successfully done such conversions, besides Myspace 'gangstas' bragging about 'OMG LIEK I MOD ME AIRSUF GLOXS WITH BLING DAIMONDS BULLETZ!!1111'.

There were myths about Japanese Yakuzas modding airsoft pistols into crude single-fire pistols, but it was proven to be a hoax. Heard that from the Airsoft Retreat forum years ago.

Couldn't help it but just want to share experience with you, its true that model weapons are illegal in Malaysia so its very hard to bring it in.  I remembered once when my bro who wanted to return with his replica duel gun was not allowed to board the plane and my dad whose in the force had to help him out.  This things if it looks like the real thing may be seized by the authorities bcz you never know when some people might use it in a robbery or something.  So much as you would like to own one, its not wise to have them in your house.