linberl, at first i was thinking cassette, but after reading the back and forth I also think changing your chainring is probably the way to go. Are you happy with the actual gear spacing of your current cassette? If so, leave it.

110 bcd chainrings are highly available and at reasonable price points. I think I have a spare 110bcd 48tooth, I'll check my parts bin.

edit: I have an FSA 48t 110, it is 4 hole. Not sure if you have a 5H or 4H crank. I am not trying to sell anything, it's yours for shipping cost, if you'd want to experiment with gear changes. Might be too much of drop downward?