How to remove enamel from wire?
Common ways of removing the insulation on enameled wire include:


Scraping the enamel carefully off with a sharp knife or blade, while trying not to nick the underlying metal wire
Melting the enamel off with a hot soldering iron in a quick motion so as not to cause a blob of carbonized enamel to stick to the wire
Sanding the enamel off with either fine sandpaper, or a polishing / sanding head on a Dremel-type rotary drill
Using a lit matchstick or a cigarette lighter to melt off the enamel, if the wire is thick enough to not get damaged in the process. Really thin "magnet wires" tend to clump up with such treatment
Not removing the enamel at all, just connecting through it to the metal wire, using either solder + flux + soldering iron, or a "vampire crimp" or "Insulation Displacement Connector" (IDC) type approach.