How do I change the text on the confirm to buy button

[ClassicalEquitation]

Hi,

 

Can someone please tell me how to change the text in the confirming order page which is at the bottom of the processing order pay.

 

It usually says something like confirm order or something along those lines.

 

I have attached a screen shop of what it currently says.

 

I am not certain where to find the file to edit so please if someone knows ?

 

Thank you

Johanne