My Saturn Vue was in a tangle with a mailbox. In the process the antenna was snapped off. The thoughtful people at Saturn supplied the antenna mount with a shear bolt but forgot to make both ends removable. The replacement antenna base costs around $50. If you have all of the tools, this repair costs less than $2.00
I will show you how to replace the antenna without replacing the base.
UPDATE: Be sure to remove the antenna before going through the car wash.
I took the car to Saturn to get a free oil change. They wash every car after service. When the car came out it had no antenna. They replaced it with the correct factory antenna and base.
Step 1: Prepare the base
Prepare the antenna base by first drilling a hole. Use the appropriate bit for the size tap and bolt you are going to use. Drill slowly, wear safety glasses. Metal shavings in the eye are not at all fun.