Remove the ham from the refrigerator (still wrapped) a couple of hours before you intend to cook it so that it can get closer to room temperature.
Preheat oven to 325°F while you prepare the glaze.
Add the butter, thyme, vinegar, fruit spread, brown sugar and Worcestershire sauce in a small bowl stir until combined.
Place the ham vertically in a glass casserole dish. Since this is a spiral cut ham and already cooked you are essentially just reheating so you don’t want to dry out the meat. Standing it up will compress the slices so less moisture escapes and allow the glaze to drip down the slides.
Using a pastry brush, brush about 1/3 of the glaze over the ham.
Loosely cover the ham with aluminum foil and then place ham in oven for about 20 minutes then baste.
Put the foil over the ham and then back into the oven cook for another 20 minutes.
Take the ham out of the oven and use the remaining glaze to baste one last time. Leave the foil off for the last 20 minutes to allow the ham to brown.
Total cooking time should be about 1 hour (about 10 minutes per pound) until the internal temperature of the ham is 110°-120° (use a meat thermometer).
When the ham is finished, remove from the oven, cover with the foil and then let rest about 10 minutes.