Can't put serpentine belt back on after replacing alternator

Which 4 cylinder there are 2 see pic we have no diagram for a 2.3L overhead cam

Sometimes it is hard putting on a new belt, the tensioner need to give you slack to get the belt on, It should be a metric bolt in the center of the tensioner and needs to use a breaker bar with socket and put it on center bolt of the tensioner and push it lightly clockwise. That will move the tensioner away from the belt giving it slack to remove the belt, to install you will have to move the tensioner the same until the belt slips over it and make sure everything is correct on the pulleys before letting off on the tensioner. Quick note, watch your fingers when you have the tensioner loosened and putting on the new belt