It has been a long time since I last worked with Angular, especially an older version like 1.2. However, I am confident that what I need can be achieved (hopefully I'm not mistaken). Below is the current code I have, and all I need to do is add a property for a CSS stylesheet, or maybe even include my CSS within quotes - either way works for me.
$scope.callxyz = function() {
var modalInstance = $modal.open({
templateUrl : 'views/xyz.html',
scope : $scope
});
$rootScope.creditCardModal = modalInstance;
};