This link gives instructions for resetting/overriding the on-board engine controller (computer).

http://www.ehow.com/how_4520585_adjust-timing-saturn-vue.html

You will need a PC loaded with GM software, a pass through cable adaper, and a Tech 2 scan tool. Apparently, it is the ignition timing that is adjusted.

However, I do not understand why the engine would need re-timing if all that was done was to replace the timing belt with an exact copy. The reference link did say that re-timing was needed only in rare cases.

Other sites mentioned that older belts had timing marks and that these marks are omitted on newer belts. In that case, examine the current position of all sprockets and marks before taking the belt off. Make sketches. If you have a digital camera, take pictures. Take enough views to insure you have plenty of information to insure correct re-asssembly.

If the new belt does not have timing marks, you may wish to add these with a marker. Compare the new belt to the old one, count teeth, and tranfer marks.

If the job seems scary, take to a professional. I understand its a lot of work and you do not want to take a chance on smashing a piston into a valve. Special tools are used to hold the sprockets and crank in place while changing the belt.