According to the Declaration of Independence who has a right to change a government if the government tries to take away these three rights?

The people have the right to change the government. One of the things you have to know when this was written it was a revolutionary idea. The world for a 1000 years had been ruled by kings with no ability for the population to change the government. To suggest that the people could change the government was very new thinking. For us, it isn't because we can change the government through voting and taking part in the government.