if your oil sump is clogged i would clean it immediately by using propper flushing liquid cos i wouldn't worry about it leaking as it will most probably restrict oil to the engine causing it to seize.
All the oil sump plug are on the lower part of the engine, in this case is the same, but you probably will no notice that because it is not a common plug, this car have a square plug.
Not exactly the simplest of questions to answer!I suggest u get a haynes manual or equivilent. Will give step by step instructions.Not a hard job if handy with a spanner!