Well, yeah, it would be easiest to do it with a legal name-change, but common-law name changes are valid, too.
Kids are a different story. You can bet he would fight tooth and nail to avoid that, and courts rarely are willing to change a child's name unless you could show that it is in their best interest--and absent unusual circumstances, courts are reluctant to do it over either parent's objection.
I know I sort of derailed the original discussion, sorry.
