hatching double yolk
I wouldn't do anything. If the shell has a pip in it, they are breathing air from the outside and resting.Just make sure your humidity is at the proper level for lock down and resist opining up the incubator unless its a dire emergency. Its better to wait and do nothing than to start poking at your eggs,and keep opening up the incubator letting the humidity escape,which puts your other eggs at risk.
Sorry didn't realize you were talking about a double yoke one. It happens,but very rarely do both survive. So don't get your hopes up to much,but I wish you the best of luck and will keep my fingers crossed for you.