Can a blind box mag be modified to either a removeable magazine or a floorplate style?
A blind box mag seems very dangerous to me.

Yes it can, but it takes a bit of work and some additional parts.

You'll need different parts depending on whether you are going to a removable box magazine, or to a fixed magazine with a floorplate which opens.

If you are in Oxford, England, the parts will undoubtedly be somewhat dificult to come by. If you are in Oxford, Mississippi, they will be easy to acquire.

If I was you, and if I was living in a place where buying and selling firearms (and having them added to/deleted from my certificate) was easy, I'd do neither. I'd just sell the existing rifle (presumably used, Remington) and I'd purchase another used one with the magazine I prefer. It would doubtless be less expensive that way, there should be no worries as to the quality of the work and its functioning, and it would likely be quicker.

If you can be more specific as to which conversion you are interested in (detachable mag, or hinged floorplate) and which make of rifle, I'm sure any number of folks here can describe for you what you will have to do and which parts you will need.

It would help to knkow what brand,and model of your rifle.There are some outfits on the market that sell kits. Some info would be helpful. van