Howdy Kesner03,
It is very easy. Take your time, and with the takedown screw as far out as it will go (and with the rifle cocked), hold the receiver in your right hand, and slap firmly a couple times behind the tang on the pistol grip. Make sure to slap straight back, and not downward. 121s are very precisely machined, and fit together tightly. Once the buttstock and trigger assembly separate, you just need to slide the bolt out. That's as far as you need for cleaning. If you want to take it apart further, that is easy also, but you will need to remove the screw that holds the forearm assembly on in order to slide the magazine out to the front.
I mostly just wipe out old oil and crud, and maybe swab the chamber. I almost never do anything to the bore in my rimfires.
Reassemble in reverse order, and again, make sure the hammer is in the full back position.
The m 121 is far easier to dismantle than the Win. m 61m and maybe some others.
forepaw
