Pro Shop is on 5th between Broadway and Demonbreun, nearer the back than the front of that side of the building but basically the middle. There's a Pro Shop Sign there and it's also called the Patron Entrance. The Hilton is right across from it. It's perpendicular to the street. So if you're coming from east of there walk through their plaza, cross 5th (easy crossing--usually blocked off) and go through the entry at the Pro Shop. If you turn left past the ticket taker, you'll go through the pro shop and need to go up the stairs to the concourse then veer right coming out of there and look to the left. If you go straight past ticket taker you'll see elevator right there. Go to 2nd floor and exit--it'll be very nearly across the concourse from where you get out.Where exactly is that "from the outside"? Street names etc
For Nissan/SoBro Entrance it's on Demonbreun (good luck pronouncing that, only locals can usually get it) between 5th and 6th. The Music City Center and its parking area is directly across from there. Go through ticketing and go straight at the concourse (unless you want some tasty barbecue, then go left!), then start to look to your left around the bathrooms.