Unfortunately our system isn't set up to process exchanges efficiently, however you are more than welcome to return the items for a full refund and then place a new order with us.
Here's a link to our returns page where you can download a form to include with your return:
https://www.lights4fun.co.uk/help/returns
If you do not have access to a printer please click here to contact our Customer Experience team who will be able to help further.