If your friend does decide he wants to convert the front hub to bolt-on, it can be done. All you need is the correct solid axle. Axles come in two diameters 9mm and 10mm generally, and with different thread pitches. You may need a fairly experienced mechanic to advise you on the proper axle and axle nuts, but after that, it's an easy job to swap it out.
My advice - put the solid axle in (about $10-15 in parts) and save the rest of his $$ for that big-ass chain lock from Krypto. Unbolt the wheel and lock it to the bike. He'll just have to learn to wear the chain like a belt.