To change and to switch out could be used interchangeably. But when using 'to change' you don't necessarily have an idea of what is being changed to, whereas with 'to switch out' you are exchanging something for something else. For instance, I could ask you to change the channel on the TV. I haven't indicated what channel to change it to, just that I want you to change it. But if I say that I need to switch out some parts in my computer the implication is that I am exchanging broken parts for parts that work. In the US when we say switch out we usually mean we are going to 'swap' or exchange something for something else.

they are quite similar and often interchangeable (but not always). switch out means to exchange one thing for another. The battery in his computer wasn't holding the charge so he switched it out with a new one. THe mechanic switched out the old, worn fan belt with a new one.

Thanks so much Gary, you always help me with my questions and I really appreciate it!

The answers that have been given are good. One minor point is that a part doesn't have to be broken to 'switch it out'. You could switch out a part to see if changing it fixes a problem.