This shows you how to add three milled slots to the part.
Create a Slot feature:
Select Make a pattern from this feature, and click Next.
Enter a Length of 1.0.
Enter a Width of 0.5.
Enter a Depth of 0.25.
Click Next.
Enter a B Angle of 90.
Enter a Radius of 1.25.
Enter a Z to 0.25.
Click Next.
Enter a Number of 3.
Enter a Spacing Angle of 120.