How do we control excess demand with the help of CRR?

CRR is increased 

CRR is a specified minimum fraction of the total deposits of customers, which commercial banks have to hold as reserves either in cash or as deposits with the central bank. Excess demand refers to a situation when people have more money leading to more purchasing power in the economy. Thus, in order to decrease the demand we need to reduce the purchasing power of the people. This can be done if we extract out the money from the economy. If we increase the CRR, the bank will have less money left for lending it to the people.