These things adapt a Onestep 2 film handling mechanism to a Polaroid pack camera (with a bellows).

Detach the film handling mechanism from a Onestep 2 by unscrewing the 4 bottom screws and removing the bottom panels, taking care not to dislodge the rollers. Unscrew the 6 screws holding it to the body of the camera and lift it out, swinging it up off the hooks on the end. Cut the ribbon cable off and wire it with the positive lead going to the switch and the other switch lead going to the inside motor terminal. Solder an additional lead to this terminal for the eject switch. Solder a negative lead to the forward motor terminal and lead them outside the unit.

Hook the adapter to the left side of the Onestep 2 back and lower it in place, then screw it down with 2 screws while holding the film door open. Reinstall the bottom covers, installing the film cover first, then the motor cover.

While holding it upside down, install the hooks facing up by pressing them into the indents. You may need to file the corners down to make it fit. Test the fit by inserting the left end into the pack camera and lowering in place. Gently press down on the back until it's seated, then press down on the hook body to engage the hooks. You may need to file down the hooks to fit your camera.

Remove the back from the camera and install the sides. They should slide into retainers on the Onestep 2 back. Reinstall the back and adapter and check the fit.

Install the left cover with the hinge pin.

Wire it to a 3.7v LiPo battery, and wire the positive lead and the switch lead to a push button switch. You may want to wire in an on/off switch to prevent accidentally pressing the eject switch.