Putting aside the question of whether congressional and senatorial term limits are a good idea, it can only happen through a constitutional amendment. It is unconstitutional for a state to impose any term limits on federally elected officials.

An amendment would require 2/3 of both houses to approve the amendment, which isn't going to happen, or a constitutional convention called by 2/3 of the state legislatures. And none of the Amendments to the constitution resulted from the latter.

But for those, who want term limits, the best answer is we already have them. The members of congress and senators are subject to election and reelection. If there is a problem with bad people in office getting reelected constantly, there is then a bigger problem with the people, who keep installing them in office.