Question [Q] help With Wave II running slowly Android

Hey guys ... when i saw this video i went mad www(dot)youtube(dot)com/watch?v=2jaIZKqBV-4 the phone in the video is the same that i have .my android is 4.4.2 cm 11.. but the one in the video is so smoothly and mine is not so can some one help me making my phone like the one in the video ? i am a Beginner so don't confuse me with hard answer and i am 14 years old
Thanks for reading this post
Sorry for my Bad English