how to fix the crankshaft?

I am planning to repalce my 98 camry timing belt by myself.
But I am not sure how to keep the crankshaft 100% fixed when we loose the crankshaft pulley bolt. Can anyone give me some advice?
Thanks for your help.

You could always remove the starter and place a screwdriver in the teeth of the flywheel to keep the engine from turning. Just be sure that it's lodged in there well before starting any work to prevent damage.

You release the timing belt Tensioner (has a spring on it).... You can remove the belt with no problems after that..... I would align to TDC (top dead center) & make sure the Distributer rotar is pointing to # 1 cycl....... After installing the new belt, release the tensioner & turn crank pulley a couple revolutions to take the slack out, retighten the Tensioner bolt.... Bob