Any Herbalist Merchant
Once you reach level 20, any herbalist merchant (potion sellers) will allow you to interact with this quest. You can start the quest at one merchant, and continue it at another, they don't really care.
Talk to an herbalist and select the 'Withdraw Skill' option. The next part of the conversation should have two options:
1. Resuscitation potion quest
The second option may be displayed in Korean, as ?'s, or as 'random' letters and junk. When first starting this quest, ignore the second option here, as it is used to open up the 'de-level' menu for resetting skills.
Now collect 10 (or more) of item 'Curst Heart'. This quest item can drop from ANY mob you fight, although it seems to be a rather rare drop. You can collect up to 300 maximum at one time. This quest will NOT block quest item drops from other quests, I have had a 'Curst Heart' drop at the same time as another quest item drop, from the same mob.
When ready to reset skill(s), bring 'Curst Heart' quest items to herbalist and go back through the conversation path used to start the quest to create your potions. When you request that the herbalist create potions (meaning, finishing the quest), he will turn as many 'Curst Heart' into potions as possible, so if you do not have even count of 10 (10,20,30,etc) you will have a few left over. Each potion created consumes 10 'Curst Heart' quest items. Creating a potion does NOT cost any gold. You can carry a maximum of 30 of these potions (not sure about multiple stacks, I've only ever had one or two at most.)
After you have created a potion, you will no longer be able to get 'Curst Heart' drops (as far as I can tell). If you want to be able to resume collecting hearts, you will have to go back through the correct 'starting quest' conversation path with an herbalist again.
Once you have 'Resuscitation Potion' items, you again talk to any herbalist, choose the skill reset quest conversation path, and choose the KOREAN option in the conversation. This option will be very obvious. If you have Korean set as your default Windows Non-Unicode language, the option will be in Korean characters, if not, it will look like gibberish. In either case, this option will open up a new window. This window will look very similar to your normal 'skill up' menu, and works very similar too.
Select the skill you want to de-level by clicking on the red 'DN' icon under it. A new window will pop up asking you to select the desired level to reset the skill to. Use the Up/Down arrows next to the skill level to select the level you wish. If you want to drop a skill more than one level, you will need ONE POTION FOR EVERY LEVEL YOU WANT TO DROP. This means you need to collect (Number of levels to remove * 10) 'Curst Heart' quest items.
WARNING!! This is a VERY expensive path. Going from level 2 to level 1 in a skill costs over 16,000 gold, and going from level 3 to level 2 in a skill costs over 19,000 gold, and going from level 3 to level 1 costs 36,000+ gold!! (I have not tried skills of any higher level.)
When you drop a skill level, you will get back 80% of the SP used to originally gain that level. Before 'purchasing' your de-level, you will be informed of how many SP you will recieve, along with the required price in gold.
Changing Mastery Level:
To lower a mastery level, you must have NO skill leveled up that requires that level of mastery. You will know when you meet the requirement for this as a red 'Level Down' button will appear next to your mastery level in the 'de-level' window. After that, it's the same process as lowering a skill level.
Any questions, comments, or quest requests are welcome. :D
And yes, I know that I posted most of this in another thread, I just thought that making this in its own thread would clean it up a bit. It also gave me an opportunity to do a few things that I could not do in the other thread (Thread title, namely).