grandia 2 SAGICE's tutorial

hi i just read sagice's tutorial on how to succesfully burn grandia 2 but he talks about burning the game on 3cds, what i dont understand is when and how would we know to switch in between the 3cds. the following is Sagice's tutorial which i am pasting as refrence.


Use ISOBUSTER and extract all of the files from Echelon's Grandia 2
US to a directory, make sure to extract both discs. Now replace
files CG10.SFD to CG17A.SFD of the "LOGO" directory of disc 1 with
the same files from the "LOGO" directory of disc 2.
Then unrar all of the files from MysticWar's fix to BTL directory of
the Grandia 2 US. Now copy the Grandia 2 directory you made 2 times
so you have 3 directories that are exacly the same. Now rename the
directories to "Disc1" "Disc2" and "Disc3" it has to be 3 discs
because if you try to replace the bad files on disc2 like with disc1
the game will be too big, and this way you don't have to rip out the
inro movie. Next delete all the files except Staff.pvr from the
"LOGO" directory in the "Disc2" and "Disc3" directories. Now goto
the "LOGO" directory in "Disc1" and cute files CG08.SFD to CG12.SFD
and paste them in the "logo" directory of "Disc2". Now goto the
"LOGO" directory in "Disc1" and cute files CG13.SFD to CG17A.SFD
and paste them in the "logo" directory of "Disc3". Now replace all
the missing files in each directory with file CG10.SFD of the
original Echelon release just rename it to the same name as the
missing files. Now burn the CDs using Nero with LEVEL 2, MODE1,
JOLIET settings. If you have any questions you can find me on Efnet
and Undernet in #DCISOS. And please NO REQUEST, I don't rip DC games!
I don't know how, so don't ask. But if you would like to tell me how
I would apreciate it lol.