The front piece is removed by a 2.5mm allen wrench, but don't do that. Do not try to permanently install the empeg. There are a bunch of reasons not to, not the least of which is that leaving it in the car in extreme temperatures (in the sun or out in the freezing cold) will kill the hard disk.

I understand that some newer cars have designed their dashboards to make it very hard to install aftermarket stereos. In that case, you either choose a different solution than the empeg, or you find an installer who is willing to do the correct customization work to make it fit.

There are lots of examples of people on this BBS who have done a decent job of fitting the empeg into a non-DIN dashboard. Have some looks at the install gallery.

In fact, I think there might be a chance that MorrisDL's 4Runner Install might give a solution to your Toyota problem. He did a trick that involved moving the position of the docking connector and doing some trimming to the dash bezel, which allowed the empeg to be removable. Perhaps your Tacoma dash is the same as his 4Runner dash, or at least similar enough so that his trick will work for you, too.