How do I add a second sidebar to my tumblr theme?

I already have a left sidebar, but I am now wanting to add another one to the right. (I have a custom theme, by the way. it’s called bubbles and I have edited it so that it has links and a background, but is essentially the same. [link below]) I’d like the second sidebar to look the same as the first one, meaning I don’t want to end up with one sidebar that looks like it’s from a completely different theme as the other one. Anybody have the code? All help is appreciated. :)

bubbles theme: http://bubblestheme.tumblr.com/