Not much to it.
http://www.ericsonyachts.org/infoexchange/entry.php?132-Reversing-the-Main-Hatch
On the current boat, the forward-facing Lewmar superhatch will open to the first stop with the rope vang on if it's not tight.
It is easy to unhook the vang shackle in order to open the hatch all the way at anchor or in the slip.
I reversed the hatch on the 32-3 in order to sail to windward with it open without inviting spray in.
But it turned out that that situation did not come up very much, and a forward-facing main hatch is better ventilation when anchored.
FWIW, I don't think I'll reverse the hatch this time, rather just unsnap the vang.