In Pyramid just keep clicking 'New Game' until a King is at the top of pyramid then just play through as normal matching cards that add up to 13.
TriPeaks is harder to force a King to the top as the cards start face-down. There are 3 chances on each board that a King will be on a peak so just hope you get one and leave him until last.
Edit:
(Unconfirmed) The TriPeaks king half can easily be completed by following this guide exaclty (credit to nickersy):