Looks like there was no need to change VM IP address to access owncloud from the network. You just need to add in Network Tab local port 8080 and deselect Require Local checkmark. This will create *:8080 item which needs to be enabled. After that you can access you owncloud IP from network.
However, once you are at the login screen you will not be able to enter since you need to enter domain / IP to trusted list. For that you need to have nano editor which I was struggling with during this thread.
After so much struggle I was able to find the way how to install it and edit config.php and edit trusted list.
For anyone who would experience the same problem please do the following in Terminal:
sudo apt-get update
sudo apt-get install nano
Hope that will be useful for anyone.