This should be easy to do!
Embeds - If you want to change the text of this button on an embedded Pickaxe, then you can find it on the embed customization page. Simply click on the button text and type in new text.
Studio - If you want to change the text of the button on the Studio, simply go into the Studio Manager, click on the page with the tool, click on the “edit Page” button in the top right of the screen, click on the button text, edit it, then make sure to save changes.
Here’s a help post that contains some screenshots and detailed instructions on how to change copy across the site.