I think you need to colour the parts of the orange where the eyes and mouth are going with green. Then you use that green as the 'greenscreen' and play the talking face footage behind the orange footage, this will then show an orange with a talking face on it. You will need something like sony vegas or adobe after effects to do it.
Well I use Adobe After Effects or Sony Vegas PRO 9, there the best thing for editing or making cool effects for the video, ofc. its hard a the start, but if you push forward you can make excellent video effects and other stuff.