Before giving up on them it's worth a little experimentation. Stop them for a while, until the elbows are better, then..
Extensions to behind the head instead of to the forehead make a huge difference as far as elbow stress & muscle stimulation. In fact, I don't understand ever doing "skulls". Instead of a barbell put both hands around the end of a dumbbell-more effective muscle stimulation & easier on the elbows, especially when done on a decline. Also try using an incline or do them seated.
Do them second, following another exercise that first warms up the elbows, like pushdowns or bench dips.
This is the best exercise, if the right variation's found that doesn't hurt the joints.