First you see if he has a profile here already-- he does:
Then you see what is there already. Do you have information that is not already represented in some way? Most Mayflower passenger profiles are already pretty complete.
Because this is a project-protected profile (protected by the Mayflower Families project here), you should discuss any changes you'd like to make before doing so. You can do that by attaching a g2g question to the profile or by adding a comment on the profile.