Renaults are notoriously difficult to do timing (cam)belts on, i even know of Renault mechanics who will not touch one as a homer, but even if it's not a Renault, it's not a simple job, it has to be set just right and tensioned the same, to slack it will fly off, too tight ad it will strip all the teeth off it in one revolution, getit out of alignment and you will bend every valve in the engine, if you are somewhat knowledgeable about engines, then get a ahynes manual and by all means give it a go, but if you have never ebven opened the bonnet, then go to a garage, maybe lookig about �60 or so, as oppposed to a new engine