I'm pretty sure that Knight went out of business a short while back but you can google what you want & I'm positive you can find what you want.  I googled them up recently looking for some specific thing that I can't remember now & was surprised the amount of information resources out there.

You will need an Allen wrench if you want to remove the breech plug.  Does your model have the hex shaped hole at the rear of the breech plug?

If so, just find the wrench that fits it and turn it out.  Make sure that the spring is relaxed and the bolt is forward when you do this so that it doesn't come flying out at you.

Once the tension is off the bolt should come back easily.  The bolt handle itself should come off too.