I used the above method on my first neck i'm now making.
I used an handsaw to make the cut, a little blockplane to make the sawed edges staight and a scraper to make them glue-ready.
For glueing the peaces together I made a special set-up. I put the neck on edge on a flat workboard and clamp it. Then i put the headstock in its place (no glue yet) and traced around it with a pencil. I clamped stopblocks on the neck end and on the headstock end to stop it from shifting. Then i removed the headstock part, put glue on it, put it back in place using the pencil lines and clamped it. If you clamp the stopblocks real tight your set-up will not shift when you put clamps on the scarf-joint (with cauls). You can put a piece of waxed paper on your workboard to prevent glueing you neck to your workboard.
When everything is glued together you can surface the top of the headstock on a sanding board.
I hope that makes some sense, since i'm not English. Thats the method I use.
It's hard work but you can do it with some basic tools and the result is perfect!