When you get the the escalator that would take you down to the casino's first floor look to the left and you'll see 6-8 doors that take you to the connecting stairs down into the Wild West. The other way is to take the first bridge into Caesars which takes you to the hotel lobby and up the ramp into the second floor of Caesars casino. If you walked towards the boardwalk you'll come to escalators that will take you to the main Ballys section. The one for the Centurion garage is closer to Ballys and I believe though not sure has a escalator still operating into the Wild West section of Ballys.
There are two bridges across Pacific Ave that are connected by an inside hallway by the bus/self park area.
There's two ways to get to Ballys from Caesars and I'm not sure about 1 of them. I've searched for a floor map for Ballys and can't find one.