Bought my truck 4 years ago and have never changed the rear differential oil. When should it be changed and how do you completely evacuate the pumpkin? There's no drain hole on the bottom, only the fill-plug half way up the pumpkin.

Thanks!

Chuck
1950 Chevy 1/2 ton (all original)
1951 Chevy 1/2 ton (future streetrod)
1941 Chevy coupe
1938 Chevy coupe streetrod