I made a modification of IgorS method to install the lxde interface known from Lubuntu. Apart from that there is a more simple method to disable nodm. For this method I used Armbian_5.25 Ubuntu Xenial desktop.
First I installed the img file on a microSD card (instead of Etcher I used the Linux utility dd from cli). With this fresh microSD card I booted the Orange Pi 2. First of all I did an sudo apt-get update/sudo apt-get upgrade.
After that I installed lxdm as described by IgorS. Because I wanted to use lubuntu instead of xfce after installing lxdm I installed lubuntu: sudo apt-get install lubuntu-desktop I did not change /etc/lxdm/lxdm.conf
Then I altered the file /etc/default/nodm and changed NODM_ENABLED=true in NODM_ENABLED=false. The first time I used IgorS method to disable nodm but that method resulted in ugly warnings (which I didn't quit understand nor did I know how to solve the described problems) and after reboot I got a black screen and no interface.
After reboot I got lxdm and selected in the menu lubuntu and after login I got the lubuntu interface.
I noticed one problem. In Lubuntu the screensaver is activated but moving the mouse or touch a key on the keyboard did not activate the screen again.... After a reboot I disabled the screensaver.
