[Rust-O-Matic]

The battery tray in my '76 GMC rusted in two, and I'd like to replace it. Stupid question, but how is it put together?

The bottom tray portion and vertical support portion are sold as 2 separate pieces, so they must come apart. But I don't see any bolts holding the 2 pieces together. Am I missing something?

To clarify, this is the typical tray on the passenger side between the inner fender and core support.