Have butcher remove pelvic bone (Aitch bone) at butt
end before roasting.
Lie the ham on its side. Cut slices parallel to the
bone, removing the cushion of meat on the underside.
Or remove as one piece and slice this at an angle
against the grain. You want to be able to sit the ham
on this surface, with the main cushion of meat
accessible to carve. Sit the ham on this newly cut
flat part.
At the shank end cut a V shaped wedge between the shin
bone and the main leg bone. This lets you get your
knife in. Cut thin slices down to the bone, moving
towards the butt end. You can release these slices by
inserting your knife in the V Shaped cut you made. The
knife is held parallel to the bone, and cuts toward
the butt end.
For second helpings, hold the ham on its side by the
shank bone. Cut parallel on either sides of the bone
to remove the meat and cut it against the grain.
For a half a ham, the same ideas apply. Release the
bottom cushion to make a flat surface. Cut at right
angles to the bone and turn your knife to release the
slices.
After carving, in the kitchen remove all remaining
meat from the bones to make deviled ham salad, ham
omelets and the like.