You can merge contacts using the Merge Parent Tool, under Tools. After reviewing the summary of information for each duplicate, select your primary, making sure other duplicates you wish to merge with that primary are checked. Once you have made all of your selections simply select the Merge button at the bottom of your screen. You can merge as many parents as you wish at one time by expanding and making your selections under each duplicate listed.
You will be warned that a parent is a duplicate in the parent profile, if you see a red bar that says, “Duplicates”, this means that person has a double. If you select that bar you will be taken to the Merge Parent Tool, but only that parent will be listed.