2d Facial expressions

Hi everyone, I’m new to this forum and I was wondering if anyone could please help me solve a problem that I’ve been trying to figure out. I’m trying to figure out a way to create the exact 2d facial expressions like the ones done on my favorite TV show Jelly Jam, http://www.youtube.com/watch?v=8KMQvL1wWMU. My friend had suggested to maybe trying doing it with texture blending. I tried looking around on this site and many others online and I’ve gotten close but not exactly what I wanted. If anyone could please point me to a tutorial or point me in the right direction to go about this I would greatly appreciate it.