can a rifle that does not have a hinged floorplate or a detachable magazine be converted to have one?

Depends on the rifle. Most stocks can be converted by a competent gunsmith.

so if i wanted to change stocks all i would need would be the new detach mag or hinged floorplate?

You could have a gunsmithinstall a floorplate or mag on your existing stock or buy a new stock with a floorplate or mag.

I don't know much about this but I'd bet you could do it cheaper by selling what you have and starting over. Custom work can be a pain in any hobby.

Tom

i am not nhappy with what i have just checking what would be involved to get one or the other.