you cant lower your ping unless u get a faster net conenction or a better connection to the nexon servers...
the trainers around that are supposed to lower your ping..just make it show 0 but your ping is still the same so it doesnt matter , plus there are no ping restrictions in kwr so no need to use that!
a way to solve ur problem and may lower the ping is trying different servers. For ex. on my net the ping is higher on server 1 and lower on server 5 and 4