ARP bolts are very tight. Take the nuts off, then put the rod in a vise with the piston up, only clamp the cap in the vise. If you have some smooth jaws its better, but if you are careful you can do it in any vise. Once you have the cap clamped in pretty good, pul up on the rod and wiggle it from front to back as it sits in the engine. It should work loose. DO NOT hit the bolts. If you can wait, I will bring my camera to the shop on Friday and post some pics of how I do it, along with an alternative method that does not use the vise, but ruins a screwdriver handle
Again .... DO NOT HIT THE BOLTS !!!
I will try to do it in the AM, but my internet at work is pretty dismal so I might not post the pics till the evening.