Ok here's the deal:
I was stupid enough to attempt a timing belt change myself without proper tools and I'm at the very last step to removing it... taking off the harmonic balancer pulley to access the crank gear... unfortunately the camrys original belt really needed changing cause it managed to snap...and according to record it needed changing in 1998... bah...
Ok so here's my problem
a) How do I get the harmonic balancer bolt out without the entire pulley moving... I don't have a rattle gun which would be very handy... and yes I have a pulley remover...
b) I'm seriously at doubt the bosch replacment belt I got is the same size as the old one...as in I think the new one is larger... Only by 1/2 an inch or so but will it matter much?
c) Should I just bite the bullet and call a call out mechanic to come round and finish the job...but they're so expensive...

 

You're in a pickle. Even with an air rachet you'd need to have a tool to hold the pulley for re-torque. You can remove the starter and hold the ring gear with a pry bar (big screw driver) but you will need a helper unless you have long arms. I've never done this so maybe someone who has can help with advice. I've heard of chain wrenches being used but you need to be carefull not to damage the pulley. I actually made my own tool with torch and welder. I've seen none on the aftermarket for sale. You should make sure your engine is not an interference engine. Turning the crank when the timing belt is off could bend a valve. But if your TB broke and you still have compression in the cylinders then you have a non-interference engine. You'll also need a torque wrench to retighten on assembly. Don't use a claw type pulley remover. Use anti-seize lub on re-assembly.

Edit: You can also use the starter to turn it off. Use a 6 point socket and long handle driver. Rest the end of the driver against a frame member and turn the starter over briefly. That works as I have tried it, pretty slick. You will need to make sure the car WON'T START by removing ignition wires. You will still need something to hold the pulley for re-torque.

The difference in belt length may present a problem as the number of teeth may affect timing. But the extra length may be taken up with the tensioner pulley. Check and recheck your TDC compression timing and alignment marks. Why Bosch replacement? Gates makes a good TB that will be the right length.