Wow Cathy - you did the impossible!!!
Top picture - a little lever releases the bobbin hatch
The bobbin in it's case lifts out and in - the bobbin threads like a normal bobbin then there is a hole in one of the little fork like things for thread to go through
In the back of the machine is a cam stack - the lever on the top releases it
it came out very easily - I think there should be a way to take them on and off - mine is on very tight right now
Then I reinstalled the cam stack. The cam stack controls are on the front of the machine next to the stitch length regulator. The machine takes industrial type round shank needles but regular needles will go in - very hard to get out though. If you get the industrial type needles you have to make the needle hole line up just so. Not hard to do once you have done it.