Look under the group, where the portafilter mounts. There are four
allen
bolts that can be loosened and the boiler rotated so the knob can be inserted.
Remove the 2 screws on top of the front of the enclosure and the 2 screws on the bottom of the back of the enclosure. This will give you access to the locking collar for the PID. Unless they've completely destroyed the enclosure or PID you'll be able to push the collar and tighten the PID.
I have an extra metal plate for the top of the Classic. Remove the 4 screws holding the cover in place. If all they did was bend the metal you should be able to remove the 2 screws and replace the metal plate.
It'll be a lot easier if we don't have to file a damage claim - unless you took pictures before you started unpacking it, and took pictures of the interior packaging so we can prove it was well packed. But if you're like me and ripped into the packaging before finding the damage we'll get nothing but grief from UPS.