remove file from /var

Using "simple backup" . The backup file is created in /var, which is owned by root.
I, the owner and only user of this computer, do not have the correct permissions to delete the old backup files.
How do I 1) either make myself "root" or 2) in another way change the permissions for that folder.
I am aware of sudo and gksudo, but have not been able to find the correct commands to effect either of the above choices.

I would appreciate some help