Concentrate on the center red, imagining it is the center of your being or your first chakra, root. Chant AUM or AEIOUM with one long exhaled breath. Take a deep inhale and chant MUOIEA (AEIOUM backwards.) A(hhh) is the red. As you sing past U to M, expand your vision in all directions; moving from the orange ring out through the green, blue. At violet, your eyes might be a little out of focus, but concentrate your attention on the white or pale violet ring about halfway to edge of the figure. You will be singing MMMMM. As you chant MUA, contract your visual field step by step through the rings of colors back to red.
Sounding beyond
After sounding your aura, expand through chakra shells of the beyond. Starting in the center red, chant AEIOUM to your pale violet outermost chakra shell. Take a breath in M and continue on out, chanting backwards, MUOIEA, out into the beyond. At this point (and it is a point, even though it appears as the outermost ring on the chart) you could stay to meditate or perform another aspect of your practice.
When you are ready to return, chant AEIOUMMUOIEA, following the sphere colors back to your red root.