Keep in mind there are two completely different issues you're dealing with here:

1. Removing the empeg.

2. Getting the factory stereo back in and working.

Depending on the way the factory stereo was designed, and depending on what the installer did, (2) might be more work than you're prepared for. If you had a pro install the empeg, then you might need another pro to reinstall the factory stereo.

Reason: Most factory stereos are self-amplified, whereas the empeg needs an external amplifier. So there's a chance that the installer had to put in an external amplifier, and had to do some wiring tricks to make said amplifier work. Those tricks would need to be carefully reversed (and the external amplifier removed). Even if he was using wiring harness adapters, there still might be some gotchas. Even if your factory stereo was externally amplified, there might be some wiring tricks the installer did, or converter boxes installed, to adapt the empeg to the external factory amplifier.

If you're lucky it'll just plug back in easy as pie, but I'm saying don't count on it.

There's also the issue that some dashboards need to be carefully dismantled in order for the installation/removal to work without damaging stuff. Don't assume that it'll be enough to just bend the tabs and yank the sled. It might be, but it might not be, I don't know about that model of car. I'm just saying, proceed with caution.