It's very easy to switch class. Let's say you have a lynn and you want to become a fiona, preserving everything.
1º Create a fiona ingame, just remember the name.
2º Now we need a fake ID to swap things. Go to dbo.Character and create a row with ID 777.
3º Set the names of the 2 characters and run this query (change originalChar and newChar with the names):
Code:
DECLARE @player1 bigint = (SELECT ID FROM dbo.CharacterInfo WHERE Name LIKE 'originalChar');
DECLARE @Player2 bigint = (SELECT ID FROM dbo.CharacterInfo WHERE Name LIKE 'newChar');
UPDATE dbo.Costume SET CID = 777 WHERE CID = @player1;
UPDATE dbo.Costume SET CID = @player1 WHERE CID = @Player2;
UPDATE dbo.Costume SET CID = @Player2 WHERE CID = 777;
UPDATE dbo.Skill SET CID = 777 WHERE CID = @player1;
UPDATE dbo.Skill SET CID = @player1 WHERE CID = @Player2;
UPDATE dbo.Skill SET CID = @Player2 WHERE CID = 777;
4º Now go to dbo.CharacterCostume and change the class, level and AP of the desired character.
5º Done! That way you preserve items and quest, while losing appearance and skills.