Edit a custom dictionary
I copied and pasted the following instructions from my version of Word
(2002) - Hope this helps.
Add, delete, or edit words in a custom dictionary
On the Tools menu, click Options, and then click the Spelling & Grammar tab.
Click Custom Dictionaries.
Select the dictionary you want to edit. Make sure you do not clear its check
box.
Click Modify.
Do one of the following:
To add a word, type it in the Word box, and then click Add.
To delete a word, select it in the Dictionary box, and then click Delete.
To edit a word, delete it, and then add it with the spelling you want.