Take it to a reputable garage, or...
1. Disconnect negative battery cable.
2. Remove timing belt covers
3. Rotate the crankshaft and align the timing marks located on the camshaft pulleys and the seal plate.
4. Remove the crankshaft pulley and hub.
5. Loosen timing belt tensioner lockbolt and remove the timing belt.
6. Temporarily secure the timing belt tensioner in the far left position with the spring fully extended, then tighten the lockbolt.
7. Make sure the timing marks on the belt pulley and the engine block are aligned.
8. Make sure the timing marks on the camshaft pulleys and the seal plate are aligned.
9. Install the belt.
Basically, be careful. If you're intent on doing this yourself, spend the $20 on a repair manual.
FinnMcCool, November 2006