On my 93/94 Cav Turbo the alternator belt is tensioned via a sprung roller which you can get a 15mm (I think) spanner on and turn the whole thing to "untension" it and remove the belt. If you want to change it, then you have to remove the offside engine mount and slip it out.
To remove the cambelt, I think you have to "untension" the automatic tensioner (using an Allen key I think) and then use the slack to slide the belt off. The water pump is then held on by 3 allen key bolt (I think) that hold the pump to the block. The pump is just up and to the left (looking from the offside end of block) from the crank pulley and can be a real pain to get away from the block once these bolts are out and some gentle persuasion may be required to "break the seal".
you will need a torx socket set for the head bolts, its a 5 pointed star shape, get a set cause the whole engine bay is littered with the buggers. I think the head bolts are size E12 torx. 3/8 inch drive is best cause the extension bar will just squeeze beside the cams. If you use a 1/2 inch drive E12 torx socket, the extension bar will not fit past the camshaft and they will have to come out.
Oddball, I have recieved new bolts from Gav and they are the same as the ones that are on the car. They are a round outer and you fit a 'tool' into them. I thought a socket went over a bolt/nut and a bit went in like a screwdriver or allen key. Is this not correct?
you have female E12 head bolts, requiring a male torx bit of the same size.
btw, you'll need a thinner extension bar than normal to get at most of the bolts, unless you want to take the cams out - or a 3/8 ext bar - but if you use a 3/8 one it's got to be a quality one or you'll probably snap it.