No tools required. Maybe use a small blade screw driver if you can not open the ring with a fingernail. The ring is like used for keys. Its a coil with two ends you can start from.
Here are a couple of thoughts on the ring and pins. They are definitely more secure, so if you can learn to work with them they would be better. They don't require special tools either. The small rings are stiff, so perhaps just a small blade driver or fingernail file to open may make them easier.
Pry open with your thumbnail. Place the nail in the ring within 1/8-1/4 inch of the end to pry open. push your thumb and forefinger in opposite directions to pry open. Slip onto the clevis pin and spin on.
Pry open with the clevis pin. Use the pin to wedge the ring open.
Pry open with a small tool.
There is a tool that holds them open for installation. I think fishing shops may have the tool. Someone told me they use them on fishing gear.