It is possible. However, it is very difficult. An amendment would have to be voted on by the US Congress and passed then it would have to go to all 50 states and 3/4’s of those states would have to vote within their own state legislatures to pass this amendment - then the amendment to the US Constitution would be RATIFIED and would become US Constitutional Law.  So it’s almost impossible. Most people consider the 22nd Amendment to be a good thing. In fact, many Americans would prefer that all of Congress (House & Senate) have term limits. Our Republic was founded with an idea that civilians would enter political service and represent their geographical area for a time and then return to their lives and others would serve, etc. It has not worked out that way. Currently, the accumulation of power by being continually in power is the best way to get things for and best care for the constituents you represent.  This makes the system very susceptible to corruption. If one could only hold power for a limited time, as with the POTUS, then, there is less incentive to corrupt oneself in order to remain in power.