It's held to the frame by a ring-nut kinda thing, and if yer lucky it has little grips on the nut you can put a screwdriver to, in case you hafta hammer it loose.
It might be under a plastic cover or somethin, but it DOES come off....I should know, having mounted a 1978 Puch Maxi Front end to a 1974 Tomos rear frame.
What surprised the hell outta me was that it fit !
Take yer electrical connections and run a bit of tape with a label on it around each end, so you know what hooks up to what when you put it back on.
That would also be a nice time to reverse yer brake cables, if you wanna use that idea, as well.