I can't keep my pigs still long enough to clip their nails unless I give them something to keep their attention elsewhere, such as a carrot. Other foods don't seem to work as it doesn't distract them enough. I usually will sit Blue (who has black nails) on my bed above eye level so I can see the nails clearly- but if your piggies are anything like mine, they will hide their feet. I will gently hold his feet and cut very small pieces off the nail until I get it to where I want it. I'm sure I could cut a lot more but it is particularly difficult since they are extremely dark. I have cut the quick in the past, but the bleeding stopped quickly. Being a new piggy owner, I freaked out and jumped on here just to check that I didn't need to do anything.
It's ten times easier to clip Ollie's nails, which I can see the quick in very easily. You just have to figure out where they are comfortable sitting and what their favorite food is and go from there, I think. Again, new piggy owner sooo.. just throwing my opinion out there. Learning every day x3