Adult to teen conversion mesh help required

[Lion-O]

Greetings and Salutations!  I am currently in process of converting some Fitchick adult meshes into teen ones.  Since this is my first one, I read the related material here and at MTS2, and thought I did an okay job...apparently not.  I used the extended manual edit to make the neck match the maxis teen neck.  I aligned normals and made sure all the bone assignments in the neck are the same.  I missed something along the way because there is that visible line at the neck. How can I correct this?  Thank you for any assistance.

[BlooM]

You also need to copy the normals
I always use Wes H his normal and vertex data merge tools.
Import a original teen mesh and put it on top, use the normal data tool to copy the normals.(by selecting both verts and use the merge command from the vertex menu)
If you have his latest unimesh plugins you have the tools already in Milkshape.
Assigning a shortcut(key) to em makes it so easy to fix seams wether its normals or vertices.

[Lion-O]

Thank you, oh mighty Bloom, keeper of vast meshing knowledge, for your fast response.  However, being the moron that I am, your suggestion did not work.  When I selected the verts around the neck and hit normal date merge, the neck area turned into this:  , which looks even funkier in BodyShop.  The vertex data merge collapsed everything to a single point.  Is that something that I need to do at the very beginning, before I save or export the mesh?  Also, is there anyway you could dumb the process down a bit more for my benefit?    Thanks again.

[BlooM]

You need to import a reference mesh(default teen) and and your custom teen mesh.
Put the default teen on top of the mesh list.

Then select one vertice, actual 2, the one from the original and the one from the custom teen but they are on the same spot, then hit the normal data merge tool.
On your screenshot you selected the whole neck, you have to do them one by one.