were is the drain plug in my xtreme?

I take it you mean the oil drain?
Dont know your specific machine but most mowers have a drain plug on the underside of the cutting deck.
*Run fuel tank empty remove spark plug lead and tip machine on its side with airfilter uppermost.
The drain plug is normally a square plug on lower engine casting.

If there is no oil plug then drain oil out of the oil filler by tipping machine as detailed above*

Maurice
April 2011