Look at the picture above.
Hold the part of ① with your right hand and hold the part of ③ with your left hand.
You can see a round hole on the left side of ②.
Put the little finger of the right hand from the front of mbira.
The thumb and index finger of the right hand and the thumb of the left hand are not used for holding the mbira, but should be put on the front of the mbira.
The three keys on the right side of Mbira (④) are played with the right thumb.
The other keys on the right side of Mbira (⑤) are played with the right index finger.
All keys on the left side of Mbira (⑥) are played with the left thumb.
To produce sound, flip your thumb from top to bottom, and your index finger from bottom to top.
Please refer to the video below.