Technically, all partnerships go through dissolution and "winding up" regardless of the circumstances. If you've been doing business with a partner, you have essentially ratified your partnership.
To dissolve, you simply quit doing business, quit renewing your license, and stop using the company name in relationships with other companies and people.
The "winding up" is nothing more than the liquidation of assets, and you'll likely have to go with even shares to all partners. Without a partnership agreement, you have an equal share implied, although you could also make a case for basing your percentage of interest by the value of assets you've contributed, the amount of time you've worked, etc. Where there are obvious imbalances, it's not an easy decision.
You might want to peruse the Revised Uniform Partnership Act (RUPA).
I've thought about your question more and I'm wondering how you could have a business license without a partnership agreement? Who's name is on the license? If there's only one name, then there's no partnership. What you have is a sole proprietorship with perhaps some investors and verbal agreements. If this is the case, the investors really have no right to the company assets. The owner has a responsibility to the investors, but what exactly that is depends on your arrangements.