May I be peaceful and at ease.
May I be relaxed.
May I be happy.
Personally I find it works better to replace "May I be" with "I am". But whatever blows your hair back works.
The second stage of the meditation is outward as you focus on the well-being of another. Usually this is easier to do with your lover or child and then work your way outward to other family members, then friends, then strangers, then the world, then the universe (but not all in the first night!)
So it would go something like:
May my daughter be filled with loving kindness
May she be peaceful and at ease
May she be relaxed
May she be happy
And in the act of meditation on your own well being and then the well being of others it becomes easier to have these thoughts throughout the course of your regular life - and as thoughts form the basis of our actions our actions then become more compassionate.
Until that sorry bastard slammed my hand with the door yesterday - which made all my loving kindness flee in the face of my desire to clock him one.

-Dana (still working on all this crap myself) Sheets