To delete a Hanja from the User Dictionary, proceed as follows:
In the Hangul: field type the Hangul word associated with the Hanja you seek in your User Dictionary.
Commit this Hangul input by pressing Control-K.
Click on the Find button.
This displays the Hanja in the User Dictionary scrolling list area. Otherwise scroll the list area to the Hanja you seek to delete.
Click on that Hanja to select it.
Click on the Delete button to delete that Hanja from the User Dictionary.
A delete confirmation dialog box will be displayed:
Click OK if you are sure you want to delete the Hanja. Otherwise, click Cancel.