It's easy ... sort of.
The A1k is a bit tricky maybe because of the case in general. Make sure you dont use force when opening this grand old lady.
When removing the FDD, watch out for the LED.
And when you put in the new one, watch it, too, because the wires might land just below the spindle and make a starining noise.
But that really shouldnt keep you from it.
Oh, and you're better off removing the cable from the FDD only when you seem to need force when removing it from the mainboard. Some boards had the cables soldered or glued on them, so don't try to remove them.
Have fun,
McTrinsic