Do YOU want to change baby's name?
Family knew of our baby names while I was pregnant and while they admired the girl's name, they weren't big on the boy's name. My dad was nearly sneering at it, but it was a beloved name to my husband so I didn't try to talk him out of it. I came to love the name, too, more reason not to change it no matter the opposition. It's your baby, I believe part of the process of preparing to meet and care for baby is the naming. Let the naysayers yammer on, keep baby's name as is and tell them to keep their opinions to themselves as you've already heard 'em.
However, if YOU want to change it for whatever the reason, I'd call your local county's clerk office (in the US) for steps you need to take.