Use the Search fields to locate the record that you suspect to be a duplicate.
Click Combine with Duplicate button at the top of the screen.
You will be taken to a Organization or Individual Search - for Duplicate. Enter in the search criteria for the duplicate record. Click Search.
From the Organization orIndividual Search Results - Select the Duplicate screen, select the duplicate record from the search results by clicking the Use link next to it. The original record will not be available for use as a duplicate in the search.
Examine the potential duplicate's record. If it is a duplicate of the original record, click on the Set & Save as Duplicate button at the top of the screen.
Select which contact data you want to save and which to discard by clicking the radio buttons next to your selections.
Click the Save button. The combined record page will be displayed.