Contact your state legislator and ask him to sponsor legislation to change whatever law it is you don't agree with.
because they change them! the government changes the laws because either they feel that they dont like them anymore or that it just doesnt belong
In fact, laws can be establish because of values. People creat laws depending on the values of their society, so values change laws.
I believe the Legislative branch can
Each country has legislation and procedures for such things. They are not all alike.
No. If the act was illegal at the time it was committed, it was a felony. That will remain forever unless you get the felony expunged.