Replacing tensioner
 

I will be replacing a timing belt and tensioner on my girlfriends 2000 hyundai tiburon. the 2.0L 4 cylinder. my main concern is getting the belt tightened correctly. Ive seen a few diagrams online where it shows .16 - .24 deflection inbetween the timing belt from the tensioner to the idler. What is the easiest way to get this done correctly? also how do you tighten the serpetine belt to the correct spec? thanx