Mine was from Japan. I don't think anything changed places once I had the language changed (a friend did it for me), so I'll describe how I get there now.
1. Turn on the DS and go past the warning screen. It should have a warning symbol at the top and some flashing text at the bottom.
At the bottom of the next screen you'll see a littl sun symbol on the left, an open DS symbol in the centre and a clock symbol on the right.
2. Press the open DS-shaped symbol at the bottom centre of the screen. You should see four coloured squares with symbols on them.
3. Press the pink spanner symbol. You should see three pink squares.
4. Press the globe symbol. You should see a screen with six boxes. These are the language choices.
5. Click the top left one. That should be English.
Hopefully that works for you.