------
## 最终结论
```python
import re

def change_date_format(date_str):
    pattern = r'(\d{4})-(\d{2})-(\d{2})'
    match = re.match(pattern, date_str)
    if match:
        year, month, day = match.groups()
        return f'{day}-{month}-{year}'

# Test cases
assert change_date_format("2026-01-02") == '02-01-2026'
assert change_date_format("2020-11-13") == '13-11-2020'
assert change_date_format("2021-04-26") == '26-04-2021'
```