Need help disassembling a Moen shower head

I am attempting to clean a Moen shower head model 3941 and need help understanding how to take it apart. Does the spray adjustment knob on the side pull off and allow the "guts" to slide out the front? Any tips would be much appreciated. (I have already soaked it in vinegar, but can't get it to produce individual spray streams.)

If the shower head is worth saving then soak it in CLR, if not just buy a new one. The cost of a good size bottle of CLR is $5.00+ and a shower head can be $10.00+. China made of course.