Step 1: Bend the flat part of the handle grip
Step 2: Add the round portion of the grip
Step 3: Front attachment
Weld this piece to the upper part of the handle grip you just finished (top of the yellow outline).
Hold this assembly on the wooden handle and begin drilling a 1/4 inch hole through it.
Step 4: Make the rear attachment
Put the screw through from the front. Attach a nut. Tack weld the nut in place. Tighten the screw.
Weld the corners of the angle iron to the flat portion of the handle grip. There is not a lot to reach with the welder, but this adds a lot of strength and stability to the handle grip.
Grind any rough edges that could snag gloves or scratch skin.
Your shovel now has a handle grip that will last much longer than the original plastic grip.