Stir together apricot preserves, orange liqueur and butter, simmer in a small sauce pan until butter is melted. (OR combine ingredients in a 2-cup glass measure; microwave on High 1 minute). Place pork cubes in heavy plastic bag, pour 3/4 cup apricot over to coat. Marinate at least 30 minutes. Thread pork onto 4-6 skewers (if using bamboo skewers soak in water for 20-30 minutes before using). Grill over hot coals 10-12 minutes turning occasionally. Baste often with the marinade. Warm remaining apricot sauce to boiling and serve along side kabobs if desired.