For me the best way is to use Buendia (Gil Puyat) tapos kanan sa Osmena (South Super highway)tapos kanan sa dulo (Quirino Ave.) tapos you will end up with a fork take the one on the right (pwede din left pero mas malayo IMO) this will bring you to a flyover and a bridge (forgot the name). Once nasa dulo ka na ng bridge turn right (marami kang makikitang mga motel) then left, then left again sa V. Mapa (the 2nd left not the 1st one which is one way)... Tapos just go straight turn right sa dulo and there nandyan na yung SM Sta. Mesa on your right side...
Its closed kapag gabi na pass 10PM... Otherwise its open. If its close, then take the left at the fork and that will get you to a bridge (again forgot the name) don't go up the bridge, stay at the right side and go under the bridge then turn right... Deretso na lang yun and SM Sta. Mesa is in your right side...