Please I need to convert this method into E generic, help

public void reverseHalf(ArrayList q) {

ArrayList s = new ArrayList();

int oldSize = q.getSize1();

for (int i = 0; i < oldSize; i++) {

if (i % 2 == 0) {

q.add(q.ArrayListIterator.remove());

} else {

s.push(q.ArrayListIterator.remove());

}

}

while (!s.isEmpty()) {

q.add(q.remove());

q.add(s.pop());

}

if (oldSize % 2 == 1) {

q.add(q.remove());

}

}