Lineup changes can be made directly from your team page. You can move players from bench to active positions up to five minutes prior to the scheduled start time of the game involving that player.
To move a player for the current week, that player must not have played or be within five minutes of his scheduled start time and the position you're trying to move him to can't be occupied by a player who has already played or is within five minutes of kickoff.
To change a player's position, simply select a new position (WR, QB, BN, etc.) from the player's position pull-down menu. If no pull-down is available, that player is locked for the week and his position cannot be changed.
If you're moving a player to a starting position that's already occupied, you must also adjust the position of the player occupying that position in order to complete the move. So, if you're moving a player from your Bench to a starting WR position, you must move the player currently occupying that position.
You can set your lineup for future weeks by clicking forward to the appropriate week from your team page. Be sure to save your changes for any week you edit before advancing to another week.