swapping faces????

Well here is my first post on the site!! I have two different pictures opened up on my Photoshop and would like to copy one face on the other pictures face...The pictures are slightly different in size.....and copy and paste do not work,thanks.

Copy and paste should work use the magic wand tool to select the one face then go edit and copy should work then just paste it into the other file with the other face and do what you may

ok,I have that much going now with the lasso ,cut and paste but my next problem is that the face is too big for the second head!!!It covers half of the body it is copied to????? What to do???

Free-transform (CTRL+T). Then grab one of the corner boxes and hold down shift while dragging it inwards.

free transorm (Ctrl + T)

well when you paste it, it automatically creates a new layer for it. Click on the new layer that it made with the new head on it. Then go, Edit/transform/scale. That will bring 4 boxes around the face. Hold down shift to constrain and drag the corner box in to change the size. If the face is the wrong shape you can go edit/free transform and pull or push however needed