I have been trying this for a while but have not succeeded can someone please help me with it.

Here is the Wikipedia Link for Iterative(Non Recursive )Post Order traversal in a binary tree.

The pseudo-code as given in Wikipedia is::

```
iterativePostorder(rootNode)
nodeStack.push(rootNode)
while (! nodeStack.empty())
currNode = nodeStack.peek()
if ((currNode.left != null) and (currNode.left.visited == false))
nodeStack.push(currNode.left)
else
if ((currNode.right != null) and (currNode.right.visited == false))
nodeStack.push(currNode.right)
else
print currNode.value
currNode.visited := true
nodeStack.pop()
```

The pseudo code is quite easy ,try to go through it .