Hi,
just done a cam belt change on my 94 aristo. bottom pulley has to come off to get the covers off. i went to halfords and bought a pulley kit. cost me about £15 i think.... a long socket bar is also very useful as the leverage is needed to open up the tensioner while you put the new belt on unless you have an extra pair of hands.... it looks a lot more complicated than it is. just be careful, line all the dots up before you start and make sure the new belt is put on exactly as the old belt you are taking off and you shouldnt really go wrong....