on your back shimmy under tractor and look up directly under the def tank (under blue cap) you will see a plate with a hole drilled in it.
Next to this hole you will see 3 bolts almost in a line (flat v shape actually) pointing downwards and these bolts have nuts on them that you can see when looking up.
The drain plug is up through this hole in this plate next two these three bolts that point downwards.
Flash light is big help.