If you mean how do you range/2h then watch youtube pk vids or try it out yourself. You can't be a pro without experience.
The most popular way is to range until they have about 16-20 hp (higher or lower depending on hp level) and then pull out the 2h right after an arrow is shot.
Other ways i've used are with range to scim then 2h. My personal favourite is range to short sword then 2h;p
If you can time it right it will come as 3 hits :O