Wow. A topic for a longish photo essay...
Too bad I didn't cover the installation of the new neck binding on the 620/12 in the TWO NEWBIES thread...
Remove the old binding (if the guitar or bass is varnished) by making a cut with an Exacto knife along the side seam where the binding joins the neck. The idea is to score the binding so the varnish doesn't chip. If the guitar or bass has been stripped, you won't have any CV to worry about.
Working from the top (fretboard) side, work a thin blade between the binding and the fretboard. The binding will begin to separate along the joint. Just keep moving the blade along the fretboard until the entire length is loose. Usually the marker dots will remain in place in the neck; these are not glued in and can be carefully pulled out with a tiny pair of nippers, and saved for later.
StewMac doesn't sell the correct celluloid binding anymore...all they carry is the extruded ABS plastic stuff.
Axiom is the place to go (
www.axinc.net). Try part # CW060-187 or CW060-250. It's going to be pricey, however, as in addition to your single piece of binding, which is only a few bucks, they will charge you a $25.00 hazardous material handling charge, as cellulose nitrate is classed as an explosive for shipping purposes, and can only be shipped by truck.
The cement that I use is a concoction of old binding strips dissolved in ethylene dichloride. I tape my binding to hold it in place; others use rubber bands. The EDC allows me to begin scraping and sanding in about two hours. The traditional way uses acetone with old binding dissolved in it. This takes longer to set up (usually overnight). Some people use super glue. The binding will be tough to remove with this method and super glue is messy to work with if you don't have a lot of experience with it.
The side dots, if you need them, are from StewMac, .060" diameter ABS rod, cut into 1/4" lengths and fitted into holes which are drilled after the binding is scraped and sanded. The dots are glued to stand slightly proud of the binding surface, and once the glue is dry they are sanded flush. The same procedure applies if you are re-using the old dots, BTW.
Now all you have to do is re-varnish the binding and blend into the existing finish...which is another essay.