Where to enter shortcode for up- and downgrade (Missing Manual)

Hi Guys,

obviously this [ms-membership-signup] short code is the one to use to change membership level.

However but WHERE can I enter the text to describe the various membership levels?

Tried to create a new page, named enrollment option. Placed in that the short code for RENEW a membership by using the following

[ms-membership-signup_renew_text]

but it didn't work out. Also wondering, which text is to choose as it is already named renew?

Please can you advise how to do it correctly?

Thank you
Prinz