How do I add a new tape

I am new to backup exec 2012. I have a new tape to replace an old one that is bad. I put it in the tape drive, Labled it, Selected "Inventory Now", then tried to associate it with a media set. After i did all that the label was right but the media set never changed and the overwrite protedted until never changes. How should i properly setup this drive?

Also,

Once i put a new disk in how  do i get the media properties to refresh?

THanks for the help!