According to the declaration of independence when should the people have the right to change their government

 "But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security."
So when the government abuses his power, the people can overthrow him or change him.
This is from the Declaration of Independence!