You may be able to, but I suggest trying to contact the guy you got the steps from to pull them from his.
If that isn't an option like he sold the truck or something, I suggest the best idea is to replicate the stock brackets by welding bolts to a small think steel sheet metal bracket. I believe the factory bolts right there are M12 but you can use standard like a 1/2". You can use your friends as reference or the step bar brackets themselves. That's what I had to do because my steps didn't come with the brackets yours are missing.
Note: The bracket with the bolts is accessible by removing the carpet hold-downs, fold the carpet up near the pedals to expose the body mount grommet. Remove that grommet and the bracket slips right in (or out). That's the only way to install the bracket or remove it.
'01 XLT disguised as a '03 Fx4 Level II
Big. Loud. Slow. Bright.