According to the SRO main website,
For 6D sox :
0) Go to General Sonheyon (Jangan) and do "Strange Incidents" quest
1) Go to Hunter Associate Ahmok(Hotan) and do the "Any Clues?" quest
2) Go to Merchant Associate Asaman(Hotan) to do the "Finding the Culprits" quest
3) Go to Merchant Associate Asaman(Hotan) to do the "Culprits Discovered" quest
4) Go to Hunter Associate Ahmok(Hotan) to do the "Reason for Kidnapping" quest
5) Go to Hunter Associate Ahmok(Hotan) to do the "Deciphering the Togui Document" quest
6) Go to Exorcist Miaoryeong(Jangan) to do the "Soldier's Coat of Arms" quest
7) Go to Exorcist Miaoryeong(Jangan) to do the "Deliver the Deciphered Document to Ahmok" quest
Go to Hunter Associate Ahmok(Hotan) to do the "Destroy Those Dolls!" quest
After this there is another string of quests that reportedly rewards you with a 8d sox, but I think this is a typo and it really gives you a 7d sox:
1) You have to have completed the 6D sox quests above
2) Go to Hunter Associate Ahmok(Hotan) to do the "Take Back the Souls" quest
3) Go to Hunter Associate Ahmok(Hotan) to do the "To Liberate the Souls" quest
4) Go to Exorcist Miaoryeong(Jangan) to do the "Understanding the Togui Spell" quest
5) Go to Exorcist Miaoryeong(Jangan) to do the "Soul Holder" quest
6) Go to Hunter Associate Ahmok(Hotan) to do the "Toguis on the Rise... Again" quest
7) Go to Hunter Associate Ahmok(Hotan) to do the "Down with the Toguis 1" quest
Go to Hunter Associate Ahmok(Hotan) to do the "Down with the Toguis 2" quest
9) Go to Hunter Associate Ahmok(Hotan) to do the "Down with the Toguis 3" quest
10) Go to Hunter Associate Ahmok(Hotan) to do the "Down with the Toguis 4" quest
11) Go to Hunter Associate Ahmok(Hotan) to do the "Down with the Toguis 5" quest
12) Go to Hunter Associate Ahmok(Hotan) to do the "The Fall of the Elder" quest