I am still learning Blender so bear with me.

I have a clothing article I made in Marvelous Designer. There are three groups in the mesh (Trim, Front, Back). I took the mesh into Blender for some clean up, fine adjustments to fit, and a little smoothing. I found a few triangles even though I exported quads.(It happens sometimes). So I cleaned them up by making quads. During this, I deleted faces created new vertices and 'f'illed them in. (you know the old tricks) The new faces are in the wrong group. I need to select the faces in the wrong group and move them from the front group to trim trim group. How do I do this?

Thanks