The upgrade has aborted. The upgrade needs a total of 69.3 M free space on disk '/boo

[hoboy]

I am trying to upgrade from 15.04 to 15.10
I have sudo apt-get clean. didn't help.

The upgrade has aborted. The upgrade needs a total of 69.3 M free space on disk '/boot'. Please free at least an additional 7,801 k of disk space on '/boot'. Empty your trash and remove temporary packages of former installations using 'sudo apt-get clean'.

[deadflowr]

Is /boot a separate partition?
If so, you need to try to clear out some old kernels.
Here's a quick one-liner, with a nice explanation about it
http://tuxtweaks.com/2010/10/remove-old-kernels-in-ubuntu-with-one-command/
Note: use the --dry-run option first, to see how it will go before trying it for real.

The apt-get clean command won't have any size affect on any partition except for whatever partition the /var directory is on.
So if boot is separate, then running that command won't do anything to clear space on /boot.
If that makes sense.

[hoboy]

I have followed this link:http://tuxtweaks.com/2010/10/remove-old-kernels-in-ubuntu-with-one-command/
But I am still getting the same errors.
ls -as /boot
total 159565
4 . 7883 initrd.img-3.19.0-25-generic.old-dkms
4 .. 7884 initrd.img-3.19.0-26-generic.old-dkms
1248 abi-3.19.0-32-generic 7886 initrd.img-3.19.0-27-generic.old-dkms
175 config-3.19.0-32-generic 7887 initrd.img-3.19.0-28-generic.old-dkms
1 grub 7887 initrd.img-3.19.0-29-generic.old-dkms
7860 initrd.img-3.19.0-15-generic.old-dkms 7887 initrd.img-3.19.0-30-generic.old-dkms
7860 initrd.img-3.19.0-16-generic.old-dkms 7887 initrd.img-3.19.0-31-generic.old-dkms
7880 initrd.img-3.19.0-17-generic.old-dkms 21494 initrd.img-3.19.0-32-generic
7880 initrd.img-3.19.0-18-generic.old-dkms 12 lost+found
7880 initrd.img-3.19.0-20-generic.old-dkms 162 memtest86+.bin
7880 initrd.img-3.19.0-21-generic.old-dkms 164 memtest86+.elf
7881 initrd.img-3.19.0-22-generic.old-dkms 164 memtest86+_multiboot.bin
7883 initrd.img-3.19.0-23-generic.old-dkms 3553 System.map-3.19.0-32-generic
7883 initrd.img-3.19.0-24-generic.old-dkms 6496 vmlinuz-3.19.0-32-generic
-----------------------------------------------------------------------------------------------
df -h
Filesystem Size Used Avail Use% Mounted on
udev 7.3G 0 7.3G 0% /dev
tmpfs 1.5G 9.3M 1.5G 1% /run
/dev/mapper/ubuntu--vg-root 910G 152G 712G 18% /
tmpfs 7.3G 22M 7.3G 1% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 7.3G 0 7.3G 0% /sys/fs/cgroup
/dev/sda1 236M 165M 59M 74% /boot
cgmfs 100K 0 100K 0% /run/cgmanager/fs
tmpfs 1.5G 60K 1.5G 1% /run/user/1000
------------------------------------------------
How can I increase the size of /dev/sda1 236M 165M 59M 74% /boot