Article 142 provides:

a) any provision thereof may be amended by way of addition, alteration, substitution or repeal by Act of Parliament 

Provided that-(i) no Bill for such amendment shall be allowed to proceed unless the long title thereof expressly states that it will amend a provision of the Constitution;(ii) no such Bill shall be presented to the President for assent unless it is passed by the votes of not less than two thirds of the total number of members of Parliament ;(b) when a Bill passed as aforesaid is presented to the President for his assent he shall, within the period of seven days after the Bill is presented to him assent to the Bill, and if he fails so to do he shall be deemed to have assented to it on the expiration of that period.