Sierra meets El Capitan OS installation issue I tried upgrading the software on my Macbook pro from OS El Capitan to Sierra.


I downloaded software and was installing it. Got the instruction to restart computer.
On re-starting, I find I don't have enough space to install Sierra. I am unable to get to the login menu and am stuck in the OS x Utilities Window.
Used Cmd + R to reinstall El Capitan. I get a notification saying I don't have enough space for this either. I am stuck in what seems to be no-mans-land. 
Tried entering safe mode to delete unnecessary files and folders. But even after several attempts my macbook does not go to safe mode. 


How do I restore my macbook to El Capitan? Should I erase my disk? Is it possible to enter into safe mode through some other way. 

Your direction is much appreciated.
Boot into Recovery Mode with Cmd-R
Once the "maOS Utilities" screen comes up, access Terminal from the Utilities menu in the menu bar
Delete unnecessary (or backuped) files/folders


(Soure: About macOS Recovery)