just execute this query
USE [SRO_VT_SHARD_INIT]
DECLARE @code varchar (64)
DECLARE @old varchar (64)
SET @Code = 'SKILL_MALL_MOVE_SPEED_UP_50_01'
SET @old = (Select Param6 FROM _RefSkill Where Basic_Code = @Code)
UPDATE [dbo].[_RefSkill]
SET Param6 = '600' (just change for how much u want)
WHERE Basic_Code = @code
PRINT 'Old Speed = '+@old