Where do I put oil to oil my sewing machine? The bobbin isn't winding just "whirring".?

I have a basic sewing machine, Brother XL 2230 and the bobbin won't wind, it just whirrs...but sounds as though it needs lubrication in there somewhere. I don't know where to oil it though. The manual has no instructions, I tried to take off the casing but couldn't get it apart even though I'd taken out all the screws. I read on another site that there are often holes in the casing of sewing machines where you squirt the oil in..but just a little. Should I try this?