Giving up on the AutoRx?
MOS2 is a moly additive. No point in wasting your money on it. Sometimes Napa goes clearance and if you pick it up cheap enough, then grab it all.
I could care less what someone claims of LubroMoly. I would not go out of my way for that oil. Its not worth the premium from what is available at your local stores. The damage is already done. Nothing in a bottle will fix it. Plenty of thick oils available, and methods of making an oil thicker, if you want to go that route.
You fill the manual transmission until it overflows from the fill plug. Make sure vehicle is on a level surface.
You should start spraying the transmission drain and fill plugs with
penetrating oil ... You want to spray them 3-5 times over a week or two prior to even attempting the removal.
The plugs will come off easy if you have quality metric tools.
Since Summer is coming, if you want to go thicker with the oil, and you have none left on the garage shelf, consider ANY 0w40, 5w40, 10w40(M1hm, Syntec), 5w50(Syntec), or 15w50(M1). A pint of Lucas or Honey oil additives will move you up a grade too.
You should still pull off a valve cover for inspection.