Whats the best way to replace drainage bungs on a wooden dinghy? ?

Please help me with my old but newly acquired wooden sailing dinghy which has two drainage bungs in the transom, one of which doesn't tighten anymore and lets in water. Whats the best way to replace and what should I bed the bung holder into ? Is this an easy job for a new boat owner and beginner boat DIYer.
DP, July 2010


done
bungs are on the outside of the boat but with a piece of nylon string through so that if out then they don't sink to the bottom.
Go a a chandlery and you can buy rubber bungs the shape of an ice-cream cone. Rubber bungs eventually become hard etc. You could shape cork bungs by getting them from a home brew shop.
Did this on my wooden Enterprise dinghy as part of referbishment.

Malcolm M, March 2014