在给定的文本中，找到并替换所有逗号为句号。
可以使用编程语言（如Python）中的字符串替换函数（如replace()）来实现此操作。

示例代码：

```python
text = "This is an example, with multiple commas, that need to be replaced."

text = text.replace(",", ".")  # 将所有逗号替换为句号

print(text)  # 输出：This is an example. with multiple commas. that need to be replaced.
```