Need a photoshop help !!!! idea for my cuda

i wanted to change the color of this picture ( 71 cuda ) to a grey-greenish color the plymouth kl8 darkmoostone color , its a rare color and i wanted to see the combo on this 71 cuda , i have a yellow 74 barracuda and wanted to change it all ,, a major facelift ! and take this style , but to put it back to is original color !


thx a lot , would be verry appreciated !!!