I actually did mine without removing the manifold. You will need a crow-foot wrench or a stubby open-end wrench to get up in there. Count on some skinned knuckles. I recall smashing the plastic connector to get it off as well. If the sensor is stuck, then just remove the manifold by:
-disconnecting the air hose, vacuum hoses, and electricals to the throttle body
-disconnect the three cables to the throttle pulley. REMEMBER how these go on so you can replace them (a digital or Polaroid photo helps)
-remove the fuel rail in one piece
-remove the manifold