on the back of the feed plate (don't know real word--that silver piece that covers the feed dogs) is a little notch. Put the slot from your slotted screwdriver in there, after you've removed the bobbin cover, bobbin and grey piece. Push it, tilting upwards and it lifts off. You'll be able to see lots of fuzz/lint/gunk. brush it out thoroughly then put everything back in reverse order. the silver cover first,then the bobbin thingy (I have a great vocab,huh?) then the grey thing and finally the bobbin. I try to do this routine after every project and more often if I'm sewing flannel or machine quilting something. It's pretty easy once you know how.