Put on the rubber gloves before handling the broken pieces to protect your hands from sharp edges. Clean the pieces with the dish soap and warm water to make sure there is no dust or dirt adhering to the edges. Allow the pieces to air-dry.
Use the paintbrush to paint white glue over the broken edge of one of the pieces. Cover the entire edge with a layer of glue thick enough to be visible but not thick enough to ooze much when you apply pressure.
Press the broken piece onto the place on the sculpture where it belongs. Wrap the ends of the joint with damp clay to hold the pieces together while the glue dries. If the broken piece is too small to cover just the ends of the joint, pack clay all around the repair.
Wait one hour for the glue to set, then remove the clay. Use the razor blade to carefully scrape off any excess glue and clay residue. Leave the sculpture untouched for another 24 hours to allow the glue to dry fully.
Repeat the process with any other broken pieces.