Peel off all soft parts, and tape the coil gap so nothing falls in there while sanding.
Chip away and sand all leftover glue away.
Use index cards to space the gap between pole and coil.
Use good ca glue to glue everything down.
Put some weights on center of cone, let sit for a day.
Pull out index and glue the dust cap back on.
Solder tinsel leads. (make sure leads line up before gluing down)
there are lots of threads with pics of the process out there. Just google it.
Did it to a pair of 12's...first time was successful..not too hard just be patient.