Here is a meditation to start cleaning your chakras. Sit for a few minutes and relax. When you are ready to chant, begin from bottom up. Concentrate on the chakra in your body and chant the bija mantra.
For 1st, 2nd, and 3rd chakras: inhale deeply, exhale and repeat the mantra, example: “Lam, Lam, Lam, Lam, Lam.”
For 4th, 5th and 6th chakras: inhale deeply, exhale the mantra drawn out, example: “Yyyyyaaaaaammm”.
For 7th chakra, Sahasra, be silent and listen for it.
Do about 3 cycles for each chakra. After all 7 sit for a few minutes. Then chant “Om Shanti Shanti Shanti” and you’re done.