I got my old 95 seats back to swap in and the passenger seat still had my blood on there from when I crashed.. I should have cleaned them before. I know, I know..
I was able to get about 80 percent of the blood off with some Meguiars leather wipes and serious elbow grease but I don't want to mess the leather up by rubbing too much..

Anyone have any ideas/tips to get the rest off?

goof off.......... get it at ricezone or advanced auto

I don't know of its effect on leather but Coca Cola will clean blood right off. (although It may eat through the leather as well)

With it being 2 years old, you may have to try a few different techniques. Coke works and so does Hydrogen Peroxide. If you use either, use it in small amounts, rub back and forth with the grain, wipe it with a soft cloth and then use a mild detergent and warm water. Good luck!