MX5 with a snapped Cambelt!!

[evo8]

Hi. I have been given a chance to buy a H reg MX5 Limited edition (British Racing Green, 1.6, leather etc) for about £150. The roof looks OK, rear window not split, front wing has had break fluid spilt on it, one door mirror missing, odo reads 110k miles, its a H reg, what do you expect!
The Cambelt has snapped, now I know it is supposed to be 'non-interferace' so the valves should not have hit the pistons but what is your opinion? and how much of a job is it to replace the cambelt (followers as well etc), could I do it myself? any help would be appreciated.

Regards

Andrew