Relax, the install is very easy. I don't have specific radio pictures but there are some around here or in the Boxster 986 subforum. My descriptions below should be sufficient though.
First things first...
Do you have the 4 digit security code for your radio?
If yes, keep it handy while installing. If no, then either call your dealer w/ your vin# & radio serial # to obtain (most here in the lower 48 provide gratis w/ proof of ownership) or submit this info in the lost radio code request thread in the 986 sub-forum here. Loren will post your info. Side note: once you have the code, write it on the option sticker in the front trunk and/or on the label on the top of the head unit once removed for future use as most people lose the radio card that came w/ the car.
With the keys - do NOT insert them into the radio until you are ready to pull out b/c you must have the radio out of the in dash chassis in order to remove the keys once they click & lock into the head unit.
The keys are identical but one side is marked L, the other R. This is their face up side of the radio orientation for inserting. The keys are a thin metal and therefore could hurt or even cut your hand during removal if not careful. To prevent from happening and assist in radio removal, place a screwdriver into the hole of each key. Then, pull on the screwdrivers using them as T handles. Depending on if your radio has ever been pulled before or how often, it may take considerable effort to get it to release so know you'll end up pulling on it harder than you think you should...
Do your wiring as needed and fish the cable out the back side of the chassis in dash. You can pull the carpeted trim piece on the side of the lower console to grab it from below.
(pull out about 2 inches where ready arrow is and then slide deeper into footwell to get it to release from tabs on rear)
Just a reminder for your wiring, do not disconnect any of the other plugs in the back UNLESS you have your radio code.
Once the radio is out, you'll see a long blue spring clip near the front lower portion of each side. These are what the radio keys locked into. You need to release the keys before reinserting the radio into the dash and do so by pushing in on the clip and pulling the key out simultaneously. They can be very tight so use a screwdriver to push them in if needed. As with removal, sliding the radio back into the chassis can take some effort. It will glide fairly easily until the last 2 inches. If it's hard to push before the last 2 inches then you don't have it lined up correctly and need to raise or lower front to get it into the right channel. For the last inch or so you again will need to use more force than you think is necessary.
Good luck and enjoy being able to use your ipod in your Porsche.
:)
PS - there is also a lost radio sticky thread in the main 996 discussion forum.
Thanks for your reply and encouragement. It took 5 mins to remove the head uniot and install the cable. It then took three hours to get the CDR 220 back into its bay. There was plenty of room, but I had to lever it up and down with much more force than anticipated. Thanks again for your help.