Download latest L2 Best system from any link below.
When download is complete, extract it to the root folder of the game, (Example: C:\Program Files\Lineage II\)
How to install the launcher:
Use the .exe that comes with it and install.
Execute the L2Best icon that will be created on your desktop.
Choose your Lineage ROOT folder as installation folder for the updater.
(Example: C:\Program Files\Lineage II\)
Wait to be done