Install Instructions part "e"

[djalecc]

Just reading thro the install instructions and on point "e" it says this

e. Change files original "index.php" (rename other.php) links.
Root folder:
mainfile.php - all call index.php rename your new default startpage name. (new portal start.php)
modules.php
header.php
footer.php
banners.php
backend.php
auth.php
admin.php
blocks folder
all files
Modules/Your_Account folder
index.php

Please explain what all this means, and what I have to do here as I don't understand it!

Thanks