To hide the Reassign button in Workflow notification a default Attribute #HIDE_REASSIGN can be used.
Add the Attribute to your message.
Set Value = Y for this attribute.
To enable it set value = N.
However for users with workflow administrator privileges, Oracle Workflow always displays the Reassign button in the Notification Details page and allows reassignment from the Advanced Worklist, Personal Worklist, and self-service home page, even if the #HIDE_REASSIGN attribute for a notification is set to Y or B.
To hide the More Information Button in Notification use #HIDE_MOREINFO Attribute and set value = Y