OK, tensioner finally arrived yesterday - Wednesday. So I fitted it last night. It was a ****** to get back into position but the lesson learned is that you want to put it in from below and shuffle it upwards into position. easier said than done but still doable. Leave the bolts out until it's in position, then put the top one in and tighten slightly (not all the way). then get the lower two 'arms' into position. Because the spring doesn't sit entirely straight you'll need to bend it a little, get one bolt in and jiggle it about a bit before you get the bolt to catch. tighten it a little bit and get the other one into place. I found it easiest to access the lowest bolt from below but if you have the car jacked up you might get both easier from below.
These cheeky little numbers were a life saver.
it's the halfords professional ratchet spanner set with mini socket set. When I first took out the allen headed bolts I found that the 3/8" drive ratchet ended up stuck against the radiator (well, the plastic flaps on the inside of the radiator) and the bolt wasn't even out yet. The ratchet spanner (10mm), adapter and allen bit let me get them the whole way out. And using a larger spanner end to end I was able to get a bit of torque on the bolts when refitting.
I don't know if there's an official order to getting the belt back on but I found it easiest to get it round all pulleys except the top one and hold a little bit of pressure upwards so it didn't fall off. Them, to get the belt on I had to put my 19mm spanner back on the tensioner bolt (the square one) and use a breaker bar to push down hard on the end to fully compress the tensioner's spring, allowing me to slip the belt onto the top pulley. If you have a spare pair of hands this would, of course, be a lot easier. I didn't. Remember to pull the pin out of the bottom of the tensioner at this point.
And Robert's your mother's brother... done. Just get the plastic etc back on.
I had to jump start the car as the battery had drained (between driving home when the pulley went and the opening and closing of doors, plus the alternator may not have been getting a full charge previously anyway) it must have drained totally. So when I started it my ABS/traction control light was on. I was slightly concerned but hoped that a quick drive would sort it... and it did. all good. And I left the battery on charge overnight so it's well topped up this morning.
I was hoping this would have fixed the squeal at full lock and it's definitely better but there's still a slight squeal. Could it be the P/S pump or pulley?