How Can I replace a value with a null or null value with a something in power query?

In Power Query, you can use the Replace Values transformation to replace a specific value with null.

1. Home tab, Under which Transform Data is selected which opens the Power Query Editor.
2. Choose the column on which the values are to be replaced.
3. Choose the Transform tab, click Replace Values button.
4. In the dialog Replace Values, into the box Value to Find put the value you want to find. If replacing Null put “null” (all lowercase).
5. In box Replace with, put the value you want to replace it with. To replace with Null put “null” (all lowercase).
6. Click OK to apply the replacement.