[Q] Question about a root topic

I want root my sgs ll ..
I am new in all this stuff , but I want to root my phone to put a new android version ..
My last version is jelly bean..I want kit kat,or something better than jelly bean.
My request is a apk,or something, to root my phone.. I want a easy apk..
I hope you understand my english, I don't know very good but I try.
Have a nice day.