What is the best way to repair a broken bathtub handle?

The best way to repair a broken bathtub handle is to first identify the cause of the breakage, then purchase a replacement handle that matches the make and model of your bathtub. Next, follow the manufacturer's instructions to remove the old handle and install the new one securely. If you are unsure or uncomfortable with the repair process, it is recommended to seek the help of a professional plumber.