I have a website done in Joomla. Is there any way that I could import that template into some program and change the design without coding?
Something like Artisteer, only Artisteer can not import templates, it can only export them.
This question appears to be off-topic. The users who voted to close gave this specific reason:
I don't know of any such software.
Your best bet would be either recreate the same template as best you can with Artisteer, or use the template and make modifcations with the help of a Firefox plugin like Firebug.
Firebug is an essential tool to see what CSS is acting on which HTML elements.
What sort of tweaks are you trying to make?