you don't have much option, really. some coils have removable wires and others do not. the non removable ones are soldered in place. only real way to find out is to rip the wires out. if a wood screw lookin thing is left in there, then they're removable. if there's a little spike thing (or nothing) left in there, then you just ruined the wires/coils.
ngk sells this goofy adaptor thing that is like a double ended wood screw that you can use to splice on new stranded metal wire.