the head layer can be duplicated,, layer via copy.  select all the background layer - delete - fill it with... green.  select the head layer and use aprilgem's tip ---  view the layers pallete   then clik on, then drag the 'layer mask'  (the one on the right )  to the little bin and click apply.

ta da.. i hope.

maybe you can drag that layer over to the illustrator document and scale to size...