what is the easiest way to get to the primary o2 sensor on my 98' disco without pulling apart the entire engine?

 

Primary O2 sensor? are you referring to the O2 sensors before the cats? The easiest way is to have someone else do it. The second is to unbolt the Y-pipe at the muffler and then loosen the pipe at the manifold so it will swing down enough to give access.

 

Study yoga.

 

Talk to sloppyjoe, he's the yoga master.