I have never been in garage when i give my car to service just because the mechanic is my friend and I trust him
so here is what @iamadee has suggested in the same thread in the post #956 just copy and pasting it below once again check for the drain bolt if not found this could help you but dont break or crack the hose pipe while removing it.
I dont know if it is the recommended way of doing it or not, but i disconnected the radiator pipe that connects radiator to engine from beneath and kept the car start to drain as much water as i could, worked fine for me.
regards
Adeel