How can I change the text of next button and previous button?

How I change the languages of next button and previous button ? It's automatically translating. I not need that. I need replace that text.  

If I understood you correctly, you need to change the "Next" and "Previous" button name. To do this, you just need to double click on the Next button and type the text you want to show on this button. Here is the screencast shows you how to do it:

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