Start by breeding that cock to both hens and produce as many offspring as possible. If they are good representatives of their breed and meet your standards, I would line-breed their best offspring to them. At this point, I would create a separate lines using the cock as one line, and the two hens as their own lines. This will get you started in the right direction. 

I will be posting my “Family Improvement Program” soon, which will give you the complete breeding program, and all its phases.

Check this program – The Practice of Line-Breeding (click here)