Cricket,
The nose is not held on by anything special. As long as nothing is broken, it pivots on two small pins. To remove it, just remove or loosen the top of the machine for clearance then open the nose piece and lift it up so the pins clear the holes and off it comes. Put it back on the same way. The pins sometimes work loose and then the nose won't stay on. Or somehow the hinges get broken. But otherwise, they are simple and easy to work with.
Joe