И в чем проблема?
<input type="checkbox" id="checbox0">checkbox0
<input type="checkbox" id="checbox1">checkbox1
<button>Click!</button>
<script>
function func2() {
var elem = document.getElementById('checbox0');
var elem1 =document.getElementById('checbox1');
elem1.checked=true;
}
document.querySelector("button").addEventListener("click", func2);
</script>