Question

how can the basic structure of constitution be changed​

Answer 1

it can be changed by rewriting it which is known as an amendment. .

Answer 2

$\mathbb{\huge{\pink{ANSWER}}}$

The basic structure doctrine is an Indian judicial principle that the Constitution of India has certain basic features that cannot be altered or destroyed through amendments by the parliament.Thus it gives extra power to court to review and strike down any constitutinal amendmentts and act enacted by the Parliament.