

I am, as will become obvious, not very handy.
I purchased and built an Ikea Kallax (4x4) shelving unit to go inside an existing built in wardrobe for my modest Lego collection.
I measured the "interior" space of the BIR, while overlooking the small return / edge for the BIR's sliding doors.
Due to the return / edge, I can't just remove the sliding doors and slide the Kallax into place as planned.
But, I do like how it looks and apart from the significant construction issue, it looks great and is fit for purpose.
Does anyone have any ideas for securing the left hand side of the Kallax once it's inside the BIR space? I was thinking perhaps shorter timber dowels to help with the internal shelves and then corner brackets / flat angle brackets to secure the main side panel?
It doesn't need to be super secure as it's only for lightweight Lego.
Can anyone help me to rectify my foolish mistake?