To amend the constitution there are two Paths to do this:
Path 1 (2 Steps)
1.- Two thirds of both houses of congress (House or representatives and senate) pass a proposed constitutional amendment, then the proposed amendment is sent to the states for ratification.
2.- Three fourths of the states, that means 38 states ratify the proposed amendment, either by the corresponding legislatures or special ratifying conventions.
Path 2 (3 Steps)
1.- Two thirds of the state legislature (34 states) ask for congress to call a convention for proposing amendments
2.- States send delegates to this convention, where they can propose amendments to the constitution
3.- Three fourths of the states (38 states) ratify an amendment approved by the convention for proposing amendments, either by their legislatures or special ratifying conventions
To pass a Law in Congress is much easier because it does not require so much consensus and this can be done in few steps:
1. The members of the House of Representatives or senate introduce the bill for consideration by congress. The house clerk assigns a legislative number for bills introduced in the House of Representatives and the senate clerk assigns a legislative number for the bills introduced in the senate.
2. A committee is assigned to study the bill, according to the subject. Usually the committee will assign the bill to the subcommittees and this will make some investigation, hearing the experts and interested parties, so they can have an opportunity to offer testimony, make a report to the full committee and the ful committee will make the recommendation to pass the bill or to put the bill aside.
3. The bill approved by the full committed is returned to the full house or senate for debate and approval. At this point members can propose amendments to the bill, add additional text or alter the bill. House and senate members vote on the version of the bill, when the bill is approved by both Chambers of Congress, it is passed for presidential action
4. If the president decides to sign the bill and is granted creates a Public Law if not President can make comments an Veto the bill and the bill can return to congress for reconsideration, but if the president does not respond within 10 days, the bill automatically becomes law. If Congress adjourns during the 10 days after the bill is sent to the president and if he does not sign it, the bill is automatically vetoed, this process is known as the pocket veto.
5. Once the bill is approved by the president, the office of Federal Register assigns a number to the Public Law and proceeds to issue the corresponding copies through the government printing office and finally it is codified so that all laws fall together.