DONT PAINT THEM WITH CLEAR COAT !!!!!!!!!!!!!!!!!!
The plastic tends to crack all the way through and you will never be able to fix the housings short of buying new ones.
Use the kit instructions and sand it in layers. When you are done use scratchx to remove any fine imperfections.
Then was the housing down, let it dry and apply a light coat of soapy water.
You will need to install 3m protective film or laminex to protect the housings.
There are many how tos on this, its very simple to apply and the headlights will last for ages and look like new.
With clearcoat paint, they will be the same if not worse than before in less than 3 months if you park your car outisde.
What you have done with the kit is remove the protective coating off the headlights. All headlights have UV protective paint on them so they dont fade. Once they start to fade, the process is accelerated and the housings get eaten up alive (the lens anyways).
Have you noticed how the lights will be perfect for say 4-5 years, then dramatically deteriorate and burn up within 1 year.