Where Is The Oxygen Sensor Located At On A 1995 Chevy K1500

Where is the oxygen sensor located at on a 1995 Chevy K1500, I’m getting code 44 (O2 Sensor Lean Exhaust) & it hasn’t been replaced in the last 80k miles on the truck.

Also is it a pretty straight foward installation? like remove the wire, unbolt the sensor, then just reverse install?

Thanks,

Jim