Replacing Stock Radio With Aftermarket

[mets5706]

Ive been reading a few cases about how people have gone about replacing their stock radio with an aftermarket radio. I have a 2002 es300. This far I have purchased what I believe to be the correct pieces:

8621133170 (x1) a bracket

8621233170 (x1) a bracket

9015350010 (x6) screws

9356855016 (x4) screws

and the navigation dash piece to replace the original radio piece which I have read is exactly double din.

First, I was wondering if this is in fact possible to do and which I am almost possitive it is and do I have all the proper pieces.

Secondly, I was wondering how I should go about doing it. If I bring it to circuit city, would they be able to install it.

Thirdly, does anyone know how I can get directions for doing it.

Fourthly, is the opening (once I remove the radio) in the 2002 es300 bigg enough to fit the new double din radio in.

Fifthly, what kind of install kit if any do I need to make a double or single din radio fit.

Finally, I believe that there is still a .5" opening around the radio once it is installed, what should I get to make it look clean and where can I get it.

Thanks for any response