You need the services of a gunsmith.
Yes you can put a bipod on any rifle.
No, however you are able to get a sniper scope for all of the bolt action rifles.
you pull bolt out put bullet in and push bolt back in
No way of knowing without a serial number and model number to put to your .22cal rifle.
if it did not come with the provision to mount a scope on it you can take it to a gunsmith and have it drilled and tapped for one.
open the bolt all the way back and pull trigger and bolt will pull out do the same to put it back in
Put the safety on.....and while pulling back on the trigger (make sure gun is unloaded first) the pull the bolt rearward and remove the bolt. Putting the bolt back in is just the reverse...slide the bolt back in while pulling the trigger back first...the bolt will slide right in. JR
put the bulit in than pull the tricker back
Make sure the rifle is unloaded. Then close the bolt. Then open the bolt, but do not pull it back. Now, pull and "hold" the trigger pulled back, and then slide the bolt back and it should slide right out of the receiver. To put the bolt back in, do the reverse (hold the trigger back and slide the bolt back into the receiver, then release the trigger).
The only Winchester made lever action rifle was the model 88.I would refer you to a good gunsmith to put your model 88 lever action rifle back together again,as these rifles are complex and should not be attempted by a novice.
The JC Higgins Model 21 is a pump shotgun, not a rifle. Reassembly should be done by a competent gunsmith.
How do you put WHAT. A pellets in the rifle, a BB in the rifle, Put it back together. your question is incomplete.