How to replace pivot pin in Caroma dual flush toilet?

Hoping someone can guide me...I thought I was very clever replacing the valve seal in our cistern. However, my husband pulled the whole thing out so that I could take it down to the plumbing supplier and whilst doing that removed what I think is called a pivot pin (which is a little piece of plastic that sits somewhere in the unit so that the arm and float sit properly). When he took this little piece off, I advised him not to as how will we know where it goes and hence, he's at work and I don't know where it goes. Please help!!!