Hello. May I ask a question about Upgrading themes here?

I am trying to upgrading brighton_boat theme into Elgg1.5.And I have read Upgrading thems Docs. http://docs.elgg.org/wiki/Upgrading_themes.
And one place I couldn't undestand is 1st to 4th lines of  main css file's topic.

"Open up Elgg's main css file views/default/css.php and copy it from there - line 593 - 678."

and where should I past these css codes?

If somebody knows about this, please help me.....