There are three main ways to change data types of columns in Power Query Editor:

1. Using the Transform Menu:

1. Select the column(s) you want to change the data type for.
2. Go to the "Transform" tab on the Power Query ribbon.
3. In the "Data Type" group, choose the appropriate data type from the dropdown menu. Options include Text, Whole Number, Decimal Number, Date, Time, etc.

2. Using the Column Header Icon:

1. Click on the icon located on the left side of the column header you want to modify.
2. A list of data types will appear. Choose the desired data type from this list.

3. Using the Change Type Option:

1. Right-click on the column header you want to modify.
2. Select "Change Type" from the context menu.
3. In the "Change column type" dialog box, you can choose the new data type and optionally specify a locale if necessary (e.g., for date formats).

Additional Tips:

* Power Query will often attempt to automatically detect the data type during the initial import process.
* If Power Query assigns an incorrect data type, you can use any of the methods mentioned above to change it manually.
* For more complex scenarios, you can use M formulas to define custom data type conversions.

By following these steps, you can easily change the data types of your columns in Power Query to ensure accurate data analysis and manipulation.