If you would like to remove the music that is currently on your iPad and resync it from iTunes, you will want to deselect the sync option for Music in iTunes, click Apply, then reselect the sync option for Music and click Apply again. You may also find the following article helpful:
I have tried that but it doesn't work! (When I unselect the playlist or any other music on itunes then press sync it takes off the two added playlist on the ipad and itunes, but it doesn't take off the other songs on the ipad)
When I try to add the playlist it adds them but overrides the previous songs and making it double songs on the ipad!!