OSMC root file system full and unable to delete media

RPi2 with osmc 16GB Sd card previously worked ok until recently
memory check shows
/dev/mmcblk0p1 240M 9% used
/dev/mmcblk0p2 is 15Gb and 100% used so no space to download any more media files.
device will not auto update.
log file confirms ERROR not enough space to download.
changed setting files lists to allow file rename and delete then reboot
if i try to delete movie files from movie menu it says library path not set.
I did not setup this system up and am an old codger so if this does not make sense just kick me off the site.
further to this post how do i set the device to delete streamed media after viewing please.

If you delete files from the video library they are not really deleted.
Use the filebrowser or ssh to delete mediafiles.
You could also keep mediafiles on external storage to prevent this from happening.