Amendments can be made in the constitution in three ways, according to article 368. And they are, by simple majority of the Parliament, i.e. amendments in this category can be made by a simple majority of members present and voting, before sending them for the President's assent. The second way is by special majority of the Parliament, i.e. amendments can be made in this category by a two-thirds majority of the total number of members present and voting, which should not be less than half of the total membership of the house and thirdly by special majority of the Parliament and approval of at least half of the state legislatures by special majority. After this, it is sent to the President for his assent.
The method of amendment was borrowed from South African constitution. An amendment to the Constitution is an extremely difficult affair, and normally needs at least two-thirds of the Lok Sabha and Rajya Sabha to pass it. More than 100 amendments have been done in the constitution of India.