Take Fresh Grated Coconut and add it in the grinder along with one cup of water
Grind it and remove the paste in a muslin cloth

Now, squeeze out the milk
Repeat the process with the same grinded coconut in the muslin cloth, to remove all of the remaining milk.

Grind the grinded coconut with on more cup of water
Remove its paste in the muslin cloth again and squeeze out all of the remaining milk