If you simply wants to change the class name so it will rendered differently, below code would do the trick.
<div>
<div ng-show="loginsuccess" ng-repeat="i in itemList">
<div id="{{i.status}}" class="{{i.status}}">
<div class="listitems">{{i.item}}</div>
<div class="listitems">{{i.qty}}</div>
<div class="listitems">{{i.date}}</div>
<div class="listbutton">
<button ng-click="UpdateStatus(i.$id)" class="btn"><span>Done</span></button>
<button ng-click="changeClass()" class="btn"><span>Remove</span></button>
</div>
<hr>
</div>
This code worked for me when I had a similar requirement to render the shopped item in my shopping list in Strick trough font.