Would be very easy if I had the car here.
When you say you turned the crank and it stopped daed, I presume you didn't try to force it all? On that assumption, it sounds as if you have got the belt on wrong somehow. If you haven't forced teh crank,. it is probably no harm done, but now the fun starts.
You will have to effectively strip the belt off and line evert thing up correctly. BUT you will have to be very careful to get the pistons to neuatral, ie all away from TDC (cannot remember the crank position for this, so best checked with a straw through teh plug holes until you gat all about the same hieght). Then relining the cams - dangerous bit, followed by correct alignment of the whole lot again.
IF this is what you need to do, then procedure would be to backwind the crank as above to neutral without forcing anything, Then releasing the timing belt by undoing the tensioner. This is VEY dangerous and you MUST keep all fingers away from the cam sprockets as they will or may suddenly spring around and nothing will stop them. They will very easily remove a finger, so be warned! Just because they haven't moved doesn't mean they wont!
then having removed the belt you will need to rotate each cam via the sproket nut clockwise until lined up with the timing marks on the back cover plate, before moving its pair carefully to match. then inserting the locking took. This is agin VERY dangerous and where you are most likely to take a finger clean off. UNDER NO CIRCUMSTANCES get you fingers between the pair of cam sprokets. I cannot emphasise this enough!!!
One one pair is lined up, repeat for the other bank. Once all 4 cams are correct, refind TDC (doesn't matter which stroke as there is only one TDC until cams join in!) and lock crank. Now you can start with the belt again. The belt is fitted from crank, ANTI clockwise so crank, cam 4, cam 3, pulley, cam 2, cam 1, tensioner and finally crank./ The slack should only be on the tensioner side. So, so slack at all on right side of engine as you look from the front.
Once tensioner is on, check the alignment with the spec tool. It should be more or less right with a few thou. If so, remove the locks and rotate twice clockwise, relock crank and check with spec tool again. Any adjustments are done with either the tensioner or top guide depending on what needs moving in which direction.
Once done, remove locks and repeat until spot on.
ANY resistance at all and stop.
If you have any worries about tjhis at all, do NOT go any further until Marks DTM is back tomorrow. he will excpalin it better than I have.
Bottom line is getting all 6 pistons to a position where the valves cannot contact them. Once there you can effectively cut the timing belt off and not harm the engine. BUT I must say again, the cams may or may not decide to spring around. they give no warning and absolutely will not stop for a finger! ASUME THEY WILL MOVE!
the difficult part is getting the cams to their correct position. You get one, and whilst getting its pair, the first one springs around. Persevere. I have done it and it certainly works.
HTH