The changes that are being made are small changes made in prayers and reponses not a major overhaul of the Mass.
Among the more obvious changes are:
-- Whenever the priest says "The Lord be with you,"
the people will respond, "And with your spirit."
The current response is "And also with you."
-- In the first form of the penitential rite, the people will confess that "I have sinned greatly ... through my fault, through my fault, through my most grievous fault." In the current version, that part of the prayer is much shorter: "I have sinned through my own fault."
-- The Nicene Creed will begin "I believe" instead of "We believe" -- a translation of the Latin text instead of the original Greek text.
-- The Sanctus will start, "Holy, Holy, Holy is the Lord God of hosts." The current version says, "Holy, holy, holy Lord, God of power and might."
As you can see they are small changes, and these changes are not new, they have been happening regularly since the 2nd Vatican Council (1962 - 65), when the Mass was changed from Latin Rite to the language of the vernacular each country where practiced.