you need to be in a hardcore match, when itsays topickthe stage pickbackstage

go to main events and look through dat whole list

I have been trying to unlock it but i cant can u help me thanks

Chose Hardcore match and change arena to backstage.The Parking lot fight is backstage too.

finish the 1st challenges

for fights you ask for parking lot broal or find a cheat.

for fights you ask for parking lot broal or find a cheat ask for hardcore match. :)