"Jay, yes, a very easy job - t
"Jay, yes, a very easy job - the jets are really nothing more than a (screw) with a pointed end, for lack of a better way to explain them.
A manual will give you any particular set-up or adjustment requirement (if necessary) - but basically you simply unscrew one and replace it with the new one.
On a couple of the Merc models they had a "high altitude" version - the difference was the jets and the gears.
Lower gears also help to compensate for the poor breathing of the motor - hence the prop change (trying to make the motor act as if the gearing was lower).
However, for occassional use, simply re-jetting should do the trick for you. If you are going to make running it at high altitudes a habit, you may also wish to re-prop. But I wouldn't immediately go out and buy one.
Try it with the jets changed and determine, by rpm, if another prop is warranted."