There are two ways I know of to do it. First you can just do it in the GECK and save it.
The second and easiest way is to just change it in the FNVEdit and save and you're good to go.
We are the hollow men We are the stuffed men Leaning together Headpiece filled with straw. Alas! Our dried voices, when We whisper together Are quiet and meaningless
As wind in dry grass Or rats' feet over broken glass In our dry cellar Shape without form, shade without colour, Paralysed force, gesture without motion; Those who have crossed With direct eyes, to death's other Kingdom Remember us-if at all-not as lost Violent souls, but only As the hollow men The stuffed men.