It's not too tough if you follow a good DIY and don't rush. I had mine out a couple of years ago to do the handbrake switch, and I'll be taking it out again tomorrow to install my 997 shifter. I'll also be installing the hinge repair kit for the console lid while it is out.
Here's a good DIY:
Boxster Projects | Parking Brake Sensor Switch
and another:
Replacing the Handbrake - Porsche Boxster (986) FAQ