Use smudge and proceed clockwise round the square from the top north-west corner (as you face north) until you end at the same place. If possible empower at sunset, and as close to the three days after the full moon as you can.
Make a swirl at each corner with the smudge and ask for blessings and protection from the benign lesser earth spirits who will, if you are fortunate, take up position there (especially if you have taller rocks on which for them to make a home).
Greet each of the loftier mid-point guardians, however you picture them, by raising your smudge to the sky and then downwards to the earth. Greet each of the guardians on the first occasion with a small rounded black stone offering (you can use jet or tourmaline if you want to use a crystal but not the fiery obsidian).
Unlike archangels, a land wight may not reveal his specific name so greet him as “sacred or noble land wight of the northern land” and so on round the four directions.
You can if you wish refer to the northern direction guardian as Tiwaz the Viking spirit warrior who represents the Pole Star, the east as Odin the Viking father God, the south as Thor the mighty thunder and blacksmith God and the west as Ingvi or Ingwaz, the ancient fertility God who, according to the old sagas or legends, went anticlockwise, against the sun, that is westwards.
You can empower a temporary or large visualized square by standing in the center and pointing your smudge in the same order as you walked north-west corner, north-center, north-east corner etc. and repeating the words as you turn the smudge clockwise and anticlockwise.
If you are making a protective square of light around yourself in a dangerous place, picture staves of light rising vertically at all eight points.
Magick squares don’t need to be uncast as their energies will flow back and forth from the soil.’Re-empower a permanent magick square monthly at sunrise, on any day during the three days after the full moon