1) Second deck on south stands. Of course the scoreboard would have to be moved (no small feat).
2) more rows added to C deck (20-30?) even around the north end zone. Incorporating the concrete risers where the troopers stand would be tricky but that is what engineers are for.
3) Add a surround cover over 1/2 of C Deck.This would accent the Horse Shoe look, keep some weather off of fans, keep a lot of sound in the stadium(crazy loud). Picture something between Cowboy Stadium and Unv, of Washington.
Note; The field can not be lowered anymore as earlier mentioned and grass can not be sustained there any more because of the "tub effect" now in play as also mentioned. Also, don't we want a fast track because the Buckeyes are going to faster than 99.9% of the teams they play.