Re: Plug wire/boot failed, cant remove them.
The wire screws into the CDI. Unscrew it like decoherence said. If you find it is also glued then use a small sharp tool to dig the glue out. The new wire will screw back in. Once the wire is out you will see the threaded contact. It looks like the end of a small sheetmetal or wood screw protruding from the CDI's socket. That will screw into the core of the new wire.
You won't hurt the CDI.
Also you'll want to replace the plug boot with a good automotive quality part.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"