Now that you've found em, if not look around the reading glasses displays. Over time, I've only seen them at Walgreens, but others may carry em, and most employes won't know what your talking about. So be a Paul Hogan, and do a walk about.
Clean the inside of the lense.
Lay out the lenses, curved side down (so when you pick em up they'll be positioned correctly).
Put some warm water in the mask.
Lay one lense in the mask - about where you think it should be.
The lenses will move around but don't get excited.
Use your index finger to hold it in place, then tilt the top or bottom of the mask down so the excess water will run away from the lense insert.
Two separate lense type mask, while holding the lense insert in place, empty the water. Do the other side the same way.
Single lense, just tilt to the other side to get the water on the opposite side. Set the other lens in place and empty the water.
Just repeat the index finger, tilt and empty.
The lens is still moveable. Pull the mask strap out of the way, place the mask against your face, select something to read, perferably somewhere between elbow and hand distance, move the lenses up, down, right or left till you like it.
Once you've got the lenses in place, lay the mask face down - flat - somewhere that it will not be disturbed. I usually do this in the evening, let it set overnight, and good to go in the morning.
They (lens inserts) will "stick", however, when applying antifog I usually try to be consicious of them and use a gentlier touch around em.
For the price, an extra set in the dive bag just in case.
Expectations: These help, but don't cure. I had to go thru a few of em to get the right magnifications. They definately enhance your ability to read your gauges, it's just finding the right focal length (underwater). Do you remember how it was when your arms began to get to short, you kept moving things in and out till you got the right spot, in time you adjust.
Enjoy..........carl