Just download and install. First time you send a message with it, it will ask if you want to set as default. This has some nice improvements over stock.
https://www.dropbox.com/s/0isljrh3suoixft/NewMessanger.apk?dl=0
Sent from My Droid Ultra
https://www.dropbox.com/s/0isljrh3suoixft/NewMessanger.apk?dl=0
Sent from My Droid Ultra