That depends on multiple factors such as; what kind of watch do you have, is the watch water-resistant and of course the technician performing the work. Replacing a battery in a watch is a RISKY procedure which if not carried out according to the manufacturer's standards can lead to more damage or a total loss. Even if you decide to risk it and perform such a service make sure to ask the individual at Walmart or Target performing the service to show you their watchmaking equipment for instance to water pressure test the watch or a quartz timing machine. Another tip and this is vital one, make sure that the watch case opener they will use is actually meant to open the case-back of your watch, if the wrong key is used they will surely gauge a big hole in your case watch.