twrp on lollipop

Is the only way to install twrp to use the app? Or can i push it through with adb? I had my phone all up to date and settings all set...and then the app that installs twrp gave me a security boot error...so I had to downgrade while restoring. And now I am getting lag...and having to set it all back up.

Is there a more sure-fire way to install twrp on 5.0.1? I dont want to have to re-do everything again.

thanks