Switching is easy.
Go to https://chinesepod.com/accounts/settings/lesson/ and choose either simplified or traditional from the character set menu.
If you’re not sure what the difference is, don’t worry. Basically, people in Mainland China use Simplified, and people from Taiwan, Hong Kong, Macau, as well as overseas communities use Traditional. Neither one is better or worse, it’s up to you to choose. Luckily, the majority of them are the same, and it’s quite easy to learn one, and then switch to learning the other. However, most agree it's easier to go from learning Traditional to simplified as opposed to vice versa.
Note that certain words on the website will not be affected by these changes. For example, Lesson titles will not change, nor will grammar/ expansion headers.