how to convert to hydraulic clutch

Hi all how do you convert to hydraulic clutch do you need a different gear box or can mine be converted. 
I don't know what code gearbox I have got but it's a 1.6 engined 5 speed convertible  (d reg).

I guess you have the 020 box which is cable only, might be possible to somehow fit a slave cylinder to operate the lever which the cable currently pulls, if you are good at fabricating,  but realistically another g/box.

Hi thanks for the reply do you know anymore info about which gearbox i would need etc?