Tried this technique tonight and it works a treat. The only difference I did was heat the post and quickly press fit the plastic over the top. First one I did as per video and the top was a touch scorched. The next two I did my way but slowly pressed the plastic on. This caused a kind of lava flow on the top side. Not a problem but doesn't look real neat. The rest I pressed on quickly and the lava flow was quite thin especially near the very top surface of the plastic and end of the post. So I was able to break the over flow of causing a neater look.
Taking the posts off I just lightly wedged the post in a vice and heated the hole as per the video and lifted the plastic.
Really appreciate the video find, it really saved me a lot of heart ache and frustration. Btw I don't know if I'll install the smaller metal posts like this for the painted plastic. I might just drill the holes out a little and have a light press fit. I think this will be safer and look more professional.
