J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Cabintop hatches

Hi All,
I replaced the forward hatch a couple of years ago with a Lewmar that dropped right in, but the Lewmar cabintop hatches are a bit smaller than the old ones. Anybody have any suggestions for downsizing the openings from the old plastic hatches? I want to be able to match the forward hatch and I like the sturdiness of the Lewmars.
Doug.