Alright I made this thread since a lot of people are posting a lot of this regarding the installation of the season 3 client even if it was ONLY a guide on the download if the S3 client, hope this would help you out. This is the BEST way possible since it save you a lot of trouble patching previously released installers.
Step 1: Download the full GCPH S3 client, here's the link : ftp://ftp.levelupgames.ph/GC/
*Upon landing on this page you can download the S3 client by parts.
*You can use direct download of the files but I recommend using any download manager.Just search it on google
Step 2: If you downloaded the S3 client by parts make sure you place ALL files in ONLY 1 folder. Click the installer so ALL of the files will combine.
Step 3: You can now begin the installation of GC S3 client. BTW, if you OS is Windows 7 or Vista right click and select "Run as administrator" before running the *.EXE file.
Step 4: You will now see the Level Up! EULA (End User Licensing Agreement), which you must accept in order to install the Grand Chase client. Left-click the box “I accept the terms in the License Agreement” in order to continue the installation of the game client, By default, the Installation Folder is listed at C:Program FilesLevel Up GamesGrand Chase. Please click Browse to change the installation folders and do not install Grand Chase under Window's Program Files. Your Season 3 Client will not run if it is installed under Window's Program Files After changing the Installation Folder, press Next for the installation process to begin.
*REMINDER*
Do not install Season 3 under Window's Program Files as your client will encounter errors, please install the game client in a separate folder and/or drive (e.g. D:Level Up Games/Grand Chase).
Step 5: Select install and wait for complete installation. The program will automatically put a shortcut to the game client on your desktop.
Step 6: Click the GCPatcher MFC (3.10MB in size) to run the patcher
Step 7: Click start and wait for the loading process to complete.
Step 8: Log-in and enjoy the full features of the GCPH S3 client