set the cams to TDC(make sure the timing belt between the two cams is tight or these instructions will not work) then set the crank about 2 degres before TDC(with a little slack in the belt between the ex. cam and the crank) . loosen the tensiner then pull the tensiner tight and spin the crank(counter clock wise) to take the slack out of the belt. this shoyld take all the slack out of the belt. hope you understand that, thats how i had to do mine cuz my T belt was doing the same as yours.
steve

 

their should be very little diferance in how tight the belt is. The reason it tries to be slack at one point is bc the cam is coming off of a lobe & tries to push the rest of the way off the lobe BUT, if the tensioner is tight their shouldent be any noticable diff. Now as far as rotating it always remember that if you look at the crank you want to make the belt pull directly on the cam not on the tensioner or water pump so that would be counter clockwise.