I had gone for years with little wear on the steel edge but the last 2 years doing a small parking really wore down the edge. I recycled an old car tire to make a new cutting edge.
I used a spare circular saw with a carbide tipped blade to cut through the steel belts of the tire. It will make a mess.
If you do this, do it outdoors. The smoke that is generated is hard on the ol’ sniffer, not to mention the mess. Highly recommend hearing protection and eye protection. Outdoors with a good breeze to clear the air, you should be ok, otherwise, wear some sort of respirator.
The piece I used stayed pretty flat. I laid out the tread on a scrap piece of 2×8, took off the steel edge from the plow and lined it up. I drilled the holes for the 5 bolts, then used a bigger drill bit to ream out the holes in the tread so it would be easier to push the bolts through.
Next, it was time to find some longer bolts as the tread will add 3/8 inch. With them found, I positioned the tread/steel edge to the plow. This a bit tricky and I had to used 2 clamps to keep it in position and pressed in place while attempting to get the washer/lock washer and double nut onto each bolt. With them all on, I eyeballed the edge so that it looked reasonably level. Then tightened everything down. Next trip into town I’ll probably pick up some higher grade steel bolts because the heads on these cheap bolts will probably break off at some point after some wear and tear.