How do you access the audio system in a 1997 Toyota 4runner to replace with new system?

I have a 1997 Toyota 4runner and i would like to put a Alpine iDA-X001 in but i can't figure out how to get into the dash to remove the old and put in the new. Also is there a problem with the system i picked that it wouldn't fit in my car or would it work perfectly?|||Here is a link of instructions with pictures.