A lot of the old Kenmores had a knob on the right side of the base that could be turned to lower the feed dogs. If yours doesn't, raise the head of the machine and see if there's a thumbscrew of some type near the bobbin area. If there is, loosen it and see if that doesn't lower them. You'll still need the darning foot but you should be able to find one that will work at Hancocks---they carry several universal feet. If you can't find a way to disengage the feed dogs try making a hole in a piece of template material and taping about a 1-2" square of it over the feed dogs with the hole lining up with the needle. Make the hole big enough that the edges won't snag your thread, small enough that the feed dogs can't grab fabric through it. Make several, you may have to change them out after awhile.