Hello Rob,

I am not entirely sure where are you seeing this button as we need to look at the overall layout. Having said that, I believe that you are referring to the subscription module and you can find the language file from the following location:

/language/en-GB/en-GB.mod_easyblogsubscribe.ini

The constants used in the language file:

MOD_SUBSCRIBE_MESSAGE_SITE="Subscribe to our blog"
MOD_SUBSCRIBE_MESSAGE="Subscribe to our blog"