Sony Ericsson Xperia X10 :: Increase GAF With Alien Icons

My girlfriend recently bought a Sony Ericsson Xperia Android phone. For the most part, she loves it.

Except that Sony Ericsson has changed the emoticons in the chat application.

On my phone, an HTC-03A (aka HTC Magic), the emoticons look like little aliens. (Yes, I know they are supposed to be robots, like the Android logo, but my girlfriend thinks of them as "aliens" because they have antennae and are green).

On her phone, the Xperia, they changed the icons to use regular rounded yellow happy faces and so on.

She is miffed. She likes the aliens, and considers the phone somewhat "broken" without them.

So... suddenly it's a task in my life to see if I can change the Sony Ericsson emoticons to Android "alien" icons.

I had hoped it was a matter of simply changing some image files... however, from what I see on the web, it looks like I need to:

Gain access to a file on the phone called framework-res.apk
Copy that file to a computer.
Edit the file to put in the right icons.
Put it back on the phone

I am unclear on how exactly to do these steps. The discussions I've seen were among people who seemed to have a better understanding than me, and did not explain some aspects. For example, they took it for granted that the necessary files were accessible, however I can't see where framework-res.apk is.

I have not "rooted" an Android phone before, and I'm hoping I don't have to go to truly deep levels of phone software configuration that carries the risk of destabilizing either her phone or mine.

I'm assuming I can get the correct "alien" icons off of my phone to put on hers. (I notice they have those very same icons on this forum... is there a place I can download them as a set?)