Go To _Refobjcommon Find your Prem go to the LINK column
Go to _RefObjItem go to the ID that is your LINK #
in one of Param's Desc it show say something like [UIU1:ITEM_PRE_SILVERTAM_4W],[USU1:SKILL_MALL_PRE_APRU_GLOBAL_4W_01]
Then Go to _RefSkill and find the skill listed as before SKILL_MALL_PRE_APRU_GLOBAL_4W_01
i wanna say its Param21 thats the Lucky increase but cant be sure...
but anyways change the param to your lucky you want and do the same in the SkillData_xxxxxenc.txt and bam done!