did it amend anything?
No, but if changes had to be made in the principles it would require a Constitutional amendment.
Directive Principles
Constitutional amendment 
who said the principles should be made the basis of all future legislation Dr. Ambedkar when was it implemented? 2002 any one reason behind its implementation? Social Justice any one of its features? It aims to create social and economic conditions under which the citizens can lead a good life.
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Directive Principles [SEP] Amendments
Changes in Directive Principles require a Constitutional amendment which has to be passed by a special majority of both houses of the Parliament. This means that an amendment requires the approval of two-thirds of the members present and voting and by the absolute majority of the house – whether the Lok Sabha or Rajya Sabha.