if your going to replace the whole handle ,use a razor blade too slice down the lines where the cork rings are glued together ,then remove them ,when you get to the reel seat it’ll most likley be fitted onto a arbour either cork lined or something like masking tape .you can use a heat gun too melt the glue holding it in place then rap a cloth around it and pull/twist it off or use a Junior hacksaw (slowly & carefully) to cut the old reel seat longways ,or use a dremal to cut it off .
if its fitted direct too the blank ,then your only choice is the heat gun ,make sure you wrap making tape either side of the reel seat too protect the blank
building a handle :
http://www.hopkinsholloway.co.uk/tutorial11.php
supplies:
http://www.hopkinsholloway.co.uk/tutorial11.php