However, the Priest will remember that he is the servant of the Sacred Liturgy and that he himself is not permitted, on his own initiative, to add, to remove, or to change anything in the celebration of Mass. ‑ General Instruction of the Roman Missal, 24.
“Therefore no other person, even if he be a priest, may add, remove, or change anything in the liturgy on his own authority.” – [Cf. Second Ecumenical Council of the Vatican, Constitution on the Sacred Liturgy, Sacrosanctum Concilium, no. 22.].