The code below will do it and it needs to be put into page settings custom code header area
<script>
document.addEventListener("DOMContentLoaded", function() {
$('.terms span').first().text('J’ai lu et j’accepte');
$('.terms span').eq(1).text('');
$('.terms a').eq(1).text('');
$('.textInSeparator').text('ou');
$('.terms span').css('font-size','13px');
$('.terms a').css('font-size','13px');
});
</script>