If you want to finish the map in the quickest way possible, please refer to the attached map I made.
A 3+ player team is best. Everyone should help clear the first wave. After that, have 1 person do the 2nd wave, and 1 person do the 3rd wave, and any other players push the scalper near the bottom left. If more than one player helps with waves 2 or 3, it usually just makes things harder.
Exp rates:
All rates assume that you have T3, guild buff, and member. If you don't have member, divide by 2. If you don't have guild buff, divide by 1.2
258 hard on a 3x day: 139,164 exp
258 hard on a 2x day: 92,776 exp
258 hard on a 1x day: 46,388 exp
On 3x exp you can push all 8 trigger mobs without going below exp cap (and several extras if you need to).
On 2x exp you can push 7 mobs without going below cap. If you push 9 you will still get 64,943 exp, which is very close to cap.
Hope you enjoy!
ps: I made this map from memory, so if a few of the placements/mob types are incorrect, I apologize. Everything you need to know IS correct, though.