There are a few ways to get ready for Gracia Epilogue today.
1) If you already have Lineage II installed, you can simply patch as you normally would. The update server is up and you can get your client ready to go right now.
Uhm ok i have patched "updating" normally with Lineage2.exe, but, the login is so down for mainteance or for what? (game i see is on)
Patch notes for the update are available on the Gracia Epilogue Preview Site (http://www.lineage2.com/epilogue/patch-notes.html). The estimated maintenance period for this launch is 7am CST to 2pm CST so please plan accordingly.