Where does your new piece go when the pawn reaches the opposite side?
A pawn that has advanced and been promoted can become any piece
the player choses. And that piece goes on the square that the pawn
advanced to to be promoted. When the pawn is moved to the eighth
rank, that pawn is displaced by the chosen piece. It goes right
there. Note that the player who promotes a pawn can pick either a
queen, rook, bishop or night. Period. If that means the player
promoting a pawn is now playing with two or more queens, or three
(or more) rooks, bishops, or nights, so be it. What the player
wants, the player gets.