Soaking it in milk helps pull the livery taste out.
For mixing it with ground beef, you can chop it finely, by hand or in a FP. If you want to grate it it needs to be frozen, and then just use a hand grater.
I typically turn my liver into pate. Mixed with cream/butter/eggs (depending on recipe) and spices I find it so much less offensive. I actually like it that way.
But I will say that on a nice salad with a good dressing is actually one of my favorite ways to eat my pate. If you can stomach the liver that way, by all means eat it that way. I typically make a salad of mixed greens and sliced kumquats, top it with balls of pate and dress it with a tart vinaigrette.