The Hawkins breech plug does not come off. And yes, I know many many years ago, they made a tool to take off the breech plug. But that was short lived, and people were normally advised not to do it. If you really want the breech plug off, then take it to a gun smith. Although they might tell you that they will not attempt the job.

That is the disadvantage of the traditional rifles. The breech plug is stuck. So you have to do your work from the muzzle end down. Can I ask, why you feel the need to take it off?