I need any information on changing the cam belt. I am also replacing tensioner and pully as teh spares guy advised. I cannot see any timing marks on teh pulleys. Has any one got a workshop manual the could post those pages , or give any advice ?

I would definately do the waterpump as well whilst your at it.
Have you got as far as dismantling yet or are you at the point of still getting the parts purchased?
I done mine earlier this year and learn't a few things in the process. On the 8 valve 105 engine it's only the cam spocket and crankshaft sprocket that you have to worry about getting lined up. The diesel pump doesn't have to be timed in. There are marks on both sprockets and before you slacken off the old cam belt turn the crankshaft with a socket to TDC and you will see the cam sprocket align to a mark on the casing. I would then mark with white tipex.
Have you got a locking/alignment tool. You'll see them on ebay for about £50 and I kick myself big time because at the time one seller had them on special offer at £36 and I didn't jump in quick enough. For my money you will need at flywheel locking tool to assist with the undoing of the crankshaft bolt. I made one with a RSJ off cut but it was a bit of a pain getting it right.
The what caught me out for about 4 weeks is that the crankshaft pulley bolt is LEFT HAND THREAD. I bought a new one from main dealers (about £2) just to be 100% sure because I had been a couple of hours away from doing severe damage on mine. I was that frustrated that I nearly hocked up a 12,000lb winch to try and get it undone. Imagine the damage that would have done tightened in up instead of undoing it.
I'm sure there are some good guides in the Multipla and Stilo 1.9JTD forums on this site. I'll have a trawl tomorrow and try I find something for you if you don't have any luck.
What part of the country are you because if your relatively near to me I could pop over and show you where bits and bobs are.

Bit of an apology on my part. Hope I haven't led you up the wrong path, having to re-visit mine over last weekend to do the cam sensor, it dawned on me that you do NOT have to get the bottom crankshaft bolt undone. I had to do mine because I needed to change the crankshaft oil seal.
There are timing marks for both the crankshaft sprocket and the cam sprocket. The top cam sprocket alignment mark is an integral molded wedge shaped pointer part of the rocket cover.
If care is taken to ensure no movement of either the crank pulley and cam sprocket pulley position, it is possible to do the cam belt change without the £50 alignment kit/tool.
If you do change the waterpump (advisable), in my opinion, you do need to remove the cam sprocket cog. I initially tried to do mine without removing the cam sprocket cog and was lucky not to do permanent damage to the new ally waterpump by trying for force it in. Fortunately, I had a spare water rubber seal to replace the damaged first replacement seal. Alot safer and easier after I removed the cam cog. I had a cheap toothed locking wedged shaped tool, which I was able to bolt against the cam sprocket cog to ensure it didn't move whilst loosening the cog bolt.
Another pointer is to note the position of the original cam belt tensioner before removal. This will give you an idea of the position of the replacement new tensioner. The tensioner is spring loaded which inturn takes up the correct tension.