There are two ways to remove the nozzle and air cap. First, you can remove it by using a torch/blower to warm and cut it. This method is used without opening the unit but you'll have to replace it since it won't be reusable. The second option is you'll have to open the unit and remove the screws.
Please check the FAQ - How do I open the case of my ULV fogger to get the full instruction on removing the nozzle. To put the nozzle back, please use a rubber mallet to prevent damage.
Please follow the video instructions below.
Step 1: Video link
Step 2: Video link