How do you adjust the wiper blade on a 2001 buick?

The wiper arms were loose so I tightened them up and now they will not go all the way back down. They work great but when I shut them off they stand straight up. Whats going on???How do you adjust the wiper blade on a 2001 buick?Newer GM cars and trucks no linger have splines on the wiper arms or drives. Pop the small cover off the base or each wiper arm. Turn the wiper blades to the off position. Loosen the metric lock hex nut and turn the blade arm down against the stops and re-tighten the lock nuts.How do you adjust the wiper blade on a 2001 buick?take the wiper blades off, turn on the wipers then shut them off. put the wipers back on against the stop.