It's very easy to just walk up to the king (via walking up the side of the mountain at certain locations where it allows you to ramp up the slope - like a staircase) (and via a part of a mountain some ways off - (seems unintended))
I'm not entirely sure it was intended for you to actually be able to use these ways, However, Ironwill does greet you at a certain distance to his model - a distance which is shorter than not being up there. - So I assume it was expected that you might be able to, and maybe, intended.