Tried change lot of value but nothing happen

[FleeWater23]

Help, i need some advise for newb right here

I tried change some values for mmorpg game,the latest case i want  is change cooldown skill value into 0 sec

i tried lot of methods from forum or youtube such changing float,D,Xor method and double values(always did freeze),but there is nothing happen at all 

And what i should do when i found the value has million/billion number in order to change it?

Thanks