How to do walking meditation? I recently came across the concept of doing walking meditation, but I am not clearly aware of the technique or procedure to do walking meditation. 

Can someone help me understand this?

Thank you.
This is to be mindful about walking. Walking creates sensations in the body like:

touch of your feet on the ground
the tension of the muscles
sensations due to change of posture
sensations due to fatigue.

Whatever sensation:

If he feels a pleasant feeling,

he understands that it is impermanent;
he understands that it is not to be clung to;
he understands that there is no delight in it.

If he feels a painful feeling,

he understands that it is impermanent;
he understands that it is not to be clung to;
he understands that there is no delight in it.

If he feels a neutral feeling,

he understands that it is impermanent;
he understands that it is not to be clung to;
he understands that there is no delight in it.

If he feels a pleasant feeling, he feels it in a detached manner.
If he feels a painful feeling, he feels it in a detached manner.
If he feels a neutral feeling, he feels it in a detached manner.

Dhātu Vibhaṅga Sutta