is it possible to upgrade the hard-drive in the SAMSUNG SKY+HD STB ?

it currently has a 300Gb (160Gb personal use which records upto 30 hours HD or 80 hours SD)

I would like to put a 1Tb drive in , that should give me 860Gb personal space which would give me
about 160 hours HD or 420 hours of SD recording time

the SKY engineer says it was just a case of swapping BUT I reckon its more than that - wont I have to clone
the current drive over to new one to put the SKY software etc on?