For dismissing popover controller you can use below code in button action method.
[popoverController dismissPopoverAnimated:YES];
For changing the width you can change the frame of the popover controller not contentSize.
popoverRect = CGRectMake(x, y, width,height);
i found you are trying like this
[popOver1 setPopoverContentSize:CGSizeMake(1000.0 , 500.0) animated:YES];
//it means in increases the contentSize not the width