Ive seen a bunch of quesions on here about the Winchester 190 cleaning and disassembly. Ive done it a few times and it usually takes about an hour for a good cleaning.
Make sure gun is not loaded.. duh!
Read this first!
There is a 1/4" pin above the trigger, push it out, it doesnt take much to push it out. Use a drift punch, recomended. Pull slide action back and lock in place. Trigger assembly can be removed. Move slide action back to closed position. Pull back and tilt slide action 1/4" or so and remove locking pin, it will pull right out. Slowly work ejection/firing pin assembly block out, careful not to let bolt spring and guide fly out. After cleaning... Reassembly will take a little finesse! Insert spring and bolt guide back into spring guide hole. Set aside the slide assembly where you can get to it using your left hand. Using fingers from both hands, pinch spring against inside of barrel throat and work spring back into position, hint takes a little effort! Now while holding it their... With left hand place bolt slide action in throat when bolt spring is far enough back to allow slide action to be placed in postion. Replace locking pin. Replace trigger assembly and pin.
This may help too.