How to Unsuspend WHM operation

We are trying to delete some of the websites from our server and keep getting the following error message.

Error: The / partition on this server is running out of disk space. WHM operation has been temporarily suspended to prevent something bad from happening. Please ask your system admin to remove any files not in use on that partition.

Here is our server status information:

cpsrvd up
exim (exim-4.69-15.1_cpanel_maildir) up
httpd (2.2.8 (Unix)) up
interval up
mysql (4.1.22-standard) up
named (9.3.4) up
syslogd up
Server Load 0.17 (1 cpu)
Memory Used 39.4 %
Swap Used 11.75 %
Disk /dev/hda3 (/tmp) DMA+ 3 %
Disk /dev/hda5 (/) DMA+ 100 %
Disk /dev/hda1 (/boot) DMA+ 14

Is there another way to clear up space on the hda5 disk so we can terminate accounts that are no longer in use on the server?

 

SSH Client

Thanks, Does anyone know of a good user friendly SSH client