Instructions
Remove the soft box from the package it came in. Most soft boxes have a mounting bracket that is designed to fit into the flash unit where the reflector dish is usually mounted.
Remove the mounting bracket from the package, align the plastic or metal tabs that are on mounting bracket with the grooves on the flash unit. Insert the tabs into the grooves and turn the bracket until it locks into place.
Assemble the soft box by inserting the support rods into the box until it takes its shape. Align the mounting collar on the back of the soft box to the mounting bracket you installed on the flash unit. Position the guide indicators on the bracket and collar so they line up, and turn the soft box until it clicks into place.