You can change only the Lookup Display Name in a foreign key relationship. To change any other properties, you need to delete the relationship, add it again, and specify the properties you want.
To edit the lookup display name for a foreign key relationship between two base objects:
Start the Schema Manager.
Acquire a write lock.
In the schema tree, expand a base object and right-click
Relationships
.
The Schema Manager displays the Properties tab of the Relationships page.
On the
Properties
tab, click the foreign key relationship whose properties you want to view.
The Schema Manager displays the relationship details.
Click the
Edit
button next to the Lookup Display Name and specify the new value.
If you want, select the
Has Associated Index
check box to add an index on this foreign key relationship, or clear it to remove an existing index.