I also edited your replay to show you where you should of hit, and you also want to make sure you have enough speed behind your kicks,grabs, Skeets Etc so experiment with all your body parts and see what they will do to Uke,
and when trying to decap Uke you want to try and get him in his neck unless you have a ungodly amount of force behind you, and don't forget the pros don't get it on their first try either so if you mess up press R then when you get to or close to where it was press E to edit.