Greetings guys. Few days ago I posted above subject line and got lots of great tips. I really appreciate it. Thanks to everyone. I studied given suggestions for RPM sensor replacement and made a plan, based on my agility, and available tools.
This is how I did it. I put few old towels on the sides of the engine bay, and few 2 x 4 planks across them. Using box end ratcheted 10 mm wrench I reached down with my left hand and undid the screw (Yes, I was prone, and looking funny...but no one was there to see me).
Next I put the wrench down and pulled the screw out carefully with my left hand. Carefully I wiggled the sensor out of its hole. Unplugging it from the harness was easy. I took out the 2 dipsticks, just for bit more room. Inserting new sensor into the hole was easy. Trick was putting the screw in. I dabbed the screw head in some silicone and stuck box wrench over it. Again, with my left hand I reached under there carefully and placed the screw in its hole. In my right hand, I had a 2 foot long piece of coat hanger wire. I used it to hole the screw in place while lifting off the box wrench. So far so good. Lastly, I reached in with my left hand and started to tighten in. When it got harder, I finished it off with the box wrench. Connecting the harness was a snap. Looking at the old RPM, I could see the damage. Insulation was completely gone exposing bare wires. It's a miracle I didn't get stuck.