My SVX is leaking oil I think.

[svxsubaru1]

My svx just started about, 6 days ago leaking oil. When ever i stop, or go really slow i can see smoke that smeels like oil, and then when i look under the car there is some oil looking liquid on the exhust, passanger side. I cant tell were its coming from, but it seems like it may be coming from the valve cover gasket. How hard would it be to change it. Any prone oil problems with the SVX in that area. Thanks. Ive been checking the oil in the SVX daily to see if the oil level has been changing, I havent noticed any real change.