Как удалить id='position' в елемента в которого класс showing (класс showing меняется по очереди)

    <li id="position1" class="slide showing"></li>
    <li id="position2" class="slide"></li>
    <li id="position3" class="slide"></li>

var controls = document.querySelectorAll('.controls');
for(var i=0; i<controls.length; i++){
    controls[i].style.display = 'inline-block';
}
var slides = document.querySelectorAll('#slides .slide');
var currentSlide = 0;
var slideInterval = setInterval(nextSlide,2000);
function nextSlide(){
    goToSlide(currentSlide+1);
}
function previousSlide(){
    goToSlide(currentSlide-1);
}
function goToSlide(n){
    slides[currentSlide].className = 'slide';
    currentSlide = (n+slides.length)%slides.length;
    slides[currentSlide].className = 'slide showing';
}
var playing = true;
var pauseButton = document.getElementById('pause');
function pauseSlideshow(){
    pauseButton.innerHTML = '&#9658;'; // play character
    playing = false;
    clearInterval(slideInterval);
}
function playSlideshow(){
    pauseButton.innerHTML = '&#10074;&#10074;'; // pause character
    playing = true;
    slideInterval = setInterval(nextSlide,2000);
}
pauseButton.onclick = function(){
    if(playing){ pauseSlideshow(); }
    else{ playSlideshow(); }
};
var next = document.getElementById('next');
var previous = document.getElementById('previous');
next.onclick = function(){`введите сюда код`
    pauseSlideshow();
    nextSlide();
};
previous.onclick = function(){
    pauseSlideshow();
    previousSlide();
};