hi there,
depending on the bucket maker, the steel is likely to be not mild steel so will be difficult to drill.
you could weld on a new pre drilled for teeth cutting edge and then add the teeth as and when you need.
Always make sure you use copper coat on the treads so as to make sure nuts can easily be undone.
And never use too longer bolts nor shorter ones.
just google "weld on cutting edges" or "bolt on cutting edges" AND you will get to see the variations.
I like the bolt on ones as you can change them for rake edges etc. And some models have the pre drilled holes for adding teeth.
I also own a Kubota mini excavator and I added small weld on tooth adaptors that I just punh out the roll pin and remove the tooth.
This way i can choose a few different types of teeth or actually turn the tooth upside down so its bottom points down rather than parallel to the cutting edge.
Also I swear by a tooth tip called "tiger tooth" amazingly useful at times.
regards,
david