The drain bolt is not that hard to get off, if you have a hex set of sockets it should come off alright with a bit of muscle behind the bar without stripping the head. I wouldnt suggest trying to take it off with out hex sockets, trust me i have f**ked up a few bolts with the wrong tools lol

Thats the proper way to do it, i also didnt bother with the drain bolt when i first flushed my coolant but it doesnt do a proper job. There is about 1 or 2 litres of coolant in the block and unless you get it all out its just going to mix with the new stuff........

If you cant find the bolt post a pic of the front area of the block and someone if not me can point out the right bolt to take off.