prime contractor not wanting to pay the full contract amount; he's trying to negotiate a settlement for us to take .67 cents on the dollar
https://www.cslb.ca.gov/ has a handy FAQ sheet on this topic that you can review, and will also have the information for the surety bond company. Generally speaking, though, you will want to contact the surety company directly, in writing, to make your claim. Be detailed and include copies of relevant documentation (contract, etc.). I recommend sending your communication via Priority Mail so that you can track its receipt. When preparing your letter, be sure to note the time the bond was in place - sometimes a company's current bond is not the one that covers the time the work in question was performed, so double check the dates. When in doubt, contact both companies.