CrNk shaft sensors

Where are the crank shaft sensors located and how to instAll them both i have a 2003 Gran prix with 3.1 engine

ckp sensor "a" is located on the left side of the motor behind the harmonic balancer. the connector should be right next to the AC compressor
ckp sensor "b" is located on the lower right side below the exhaust manifold.

crank sensor "b" is the 7x sensor the goes into the side of the engine. It has one bolt. Unplug the sensor. remove the one bolt. then switch out the sensor. Lube the O ring on the new sensor to make it easier to go into the engine.

crank sesnor "a" is the 24x sensor. you remove the harmonic balancer to access the sensor.
https://www.youtube.com/watch?v=6nGE1YxUNWM