I just purchased the game and trying to figure this out. I am at the Redshirt phase of the year and I have 4 QB's and all but one of them are
Redshirts. How do I remove the redshirt on players? Thank you

You click on the player to remove the redshirt. By removing the redshirt you can't re-redshirt them though. Make sure your players were actually marked as redshirts though and aren't just marked as previously redshirted players.

It sounds like those are players that were redshirted the previous year. A player that was redshirted will always show that by their name the rest of their eligibility. For instance you would see SR(RS)

yes, and players who are currently redshirted will show a little redshirt icon next to their name on the roster grid.