Drill, and bolt with 1/2" or 5/8" grade 8 bolts.

The bucket, and the tooth bar might be medium or high carbon steel, which may make drilling the holes difficult. If that is the case, you can do what's called a local heat, right where you need the holes. That will involve an oxy-fuel torch. Hold the torch where you need the hole, soak it until the steel is yellow hot, and hold it yellow hot for 5 more seconds. Once you remove the torch place some scrap plate steel over the spot you heated. Let it cool as slow as possible. Done correctly, this will anneal the steel, which is breaking down the carbon and iron bond, making it softer.

If you successfully get your holes made, I would do end, end, middle, then between end and middle on both sides, for a total of 5 bolts. Bold heads on the bottom, nuts on the top. So the bolts would be upside down pointing toward the sky. If the nuts were on bottom, you'll get them packed with dirt, making it more difficult to get them off.

This. Just bolt it to the bucket.

Drill, and bolt with 1/2" or 5/8" grade 8 bolts.

The bucket, and the tooth bar might be medium or high carbon steel, which may make drilling the holes difficult. If that is the case, you can do what's called a local heat, right where you need the holes. That will involve an oxy-fuel torch. Hold the torch where you need the hole, soak it until the steel is yellow hot, and hold it yellow hot for 5 more seconds. Once you remove the torch place some scrap plate steel over the spot you heated. Let it cool as slow as possible. Done correctly, this will anneal the steel, which is breaking down the carbon and iron bond, making it softer.

If you successfully get your holes made, I would do end, end, middle, then between end and middle on both sides, for a total of 5 bolts. Bold heads on the bottom, nuts on the top. So the bolts would be upside down pointing toward the sky. If the nuts were on bottom, you'll get them packed with dirt, making it more difficult to get them off.