Made a mistake on marriage license before married.

My fiance and I recently got our marriage license a few weeks ago. He's hispanic so his last name on technically two last names, I kind of like both of them so I wanted to take them both since you can do that in California. His last name is Garcia Carrasco.


But for our marriage license it just said my last name would be Garcia and we both stupidly assumed that they would only add his other last name once we are officially married. I don't I don't know why we thought that but we did.
We're just now finding out that that's not the case,I know we should have known, our fault.. we have not been married yet since our wedding is in August. I want to know if it's possible to still go over to the clerk's office and quickly change this. I know it's a lot more complicated with a marriage certificate so hopefully it's not with just a marriage license, especially if you aren't married yet.Also I'm in Orange county.
Again I know I should have known better and we should have asked, so no need to tell me how dumb I was for not asking,we know now 😅 We just want to know if me can change this.