There is an alternate
and less "messy" method.
Take an egg and some pointed instrument. Carefully make a hole in one of the narrow portions of the shell. Be carefull not to knock any peices of shell inside.
Then turn the shell upside down over a bowl, and make another, identical hole on the other end. Now, gently, place your lips over this hole and blow into the egg.
As you do this, egg white is forced out the other side. When it stops running, stop blowing. If you blow too hard, the yolk will break and it will come out too. This is useful if you also need the yolk.
I have used this several times, with great success. There are also actual devices that you may pour an egg into that catch the yolk and allow the white to flow. I have never used one so I can't speak as to their worth.