こんな感じです
css
1.hoge{font-weight:bold;}
2.fuga{color:red;}
javascript
1window.addEventListener('DOMContentLoaded', function(e){
2 document.querySelector('[type=button][value=go]').addEventListener('click',function(e){
3 Array.prototype.forEach.call(document.querySelectorAll('.hoge'),function(x){
4 x.classList=[];
5 });
6 });
7});
HTML
1<table>
2<tr><td class="hoge fuga">hoge fuga</td></tr>
3<tr><td class="hoge">hoge</td></tr>
4<tr><td class="fuga">fuga</td></tr>
5<tr><td>none</td></tr>
6</table>
7<input type="button" value="go">
古い書き方
念のためレガシーな方法も書いておきます
javascript
1<script>
2function go(){
3 var n=document.getElementsByClassName('hoge');
4 for(var i=n.length-1;i>=0;i--){
5 n[i].className="";
6 }
7};
8
9</script>
10<table>
11<tr><td class="hoge fuga">hoge fuga</td></tr>
12<tr><td class="hoge">hoge</td></tr>
13<tr><td class="fuga">fuga</td></tr>
14<tr><td>none</td></tr>
15</table>
16<input type="button" value="go" onclick="go()">
もしくは
javascript
1function go(){
2 var n=document.getElementsByTagName('td');
3 for(var i=n.length-1;i>=0;i--){
4 if(n[i].className.match(/(^| )hoge( |$)/)){
5 n[i].className="";
6 }
7 }
8};