This is the output in Disk Utility:
Disk Utility cannot modify this disk because it contains CoreStorage physical volumes. Use command line distil instead.
The selected partition won't be changed.
How do I remove the partition?
It's completely empty now and I've cleared it by formatting it but I want to completely remove the partition and merge the free space back into the bigger partition.
I've tried doing this but it doesn't work in Terminal:
diskutil eraseVolume format name device diskutil eraseVolume HFS+ awer disk1s4
It didn't work:
Started erase on disk1s4 asdf Unmounting disk Error: -69879: Couldn't open disk