He didn't include the hardware or install instructions w/ the plates? Shame on him, lol.

By your pics, looks like you may need to open up the hitch slot wider with a file or something equivalent. File down both sides equally and keep checking fitment after a few filings. I'll eventually slide into place when the material is clear with the hitch.

I'll send you screws and washers for the rear plate as well. Looks like you'll need about four of them since you have the hitch version.

If you have problems aligning the bottom screws with the holes in either plates, drill out a size larger hole to allow more lining up with the screws. But not too large that the washers won't work anymore.

I'll get the hardware together and send them out tomorrow pending your address. Take care and you can e-mail me direct at rudesvx@sbcglobal.net if you have any further questions. Thanks, ron.