This is a common phone call we receive. The glass panel is factory cut, so will always fit, it’s just that it is a tight fit on purpose to seal the unit. To fit the glass side panels, simply loosen the screws at the top and the bottom of the vertical framework that hold it to the curved front rails, and this will give you the freedom to fit the glass into the vertical upright, then once you have done this, tighten up the screws to nip the curved rail back into position.