Upgrading baseband from NE4 to NJ2

I haven't upgraded my baseband/modem since I was running S3RX, so I am on NE4 baseband currently. I have been running CM12 for some time now and have no plans on going back to KK.
So I'm wondering what the best way to update to NJ2 would be. Should I download d2att_I747UCUFNJ1_bootloader_modem_4.4.2_12-3-14.zip flash in twrp, reboot then flash d2att_I747UCUFNJ2_bootloader_modem_4.4.2_8-19-2015.zip?

thanks!