Here is the way to change it in Word 2007:
- Click on the Office button
- At the bottom is a box called Word Options, click on that
- Click on Proofing on the left-hand side
- Choose Custom Dictionaries
- Click on Edit Word List
The word list is in alphabetical order. Just scroll through the list and if you want to delete something, highlight it, press delete and continue as you have time. When you are done click OK to get out of it and your changes will be saved.
One of the best kept secrets in Word 2007 is the Word Options button.