Very easy, I applied last year for my 2016 +4. I didn't really want to go into Paris, but the area starts about 1Km OUTSIDE the Peripherique, and Montlhéry is quite near Paris, in fact in 2015 my satnav took me onto it. I also took a wrong turn and ended up in that rather long tunnel, so I had to go to the end, and then return through it. There is a Péage (toll) of about €3 each way, but this does not apply to anyone with a telepéage tag - so I was very glad I had one!
I had an e-mail confirmation by return, and the sticker (level 1) by post within a week.
The only point that slightly concerns me is the sticker should be affixed on the near-side of the windscreen - in France this is the drivers side. In UK any obstruction in the swept area of the windscreen fails the MOT.
With regard to Lyon stickers are not required for the motorway, but if you leave it for any reason you're in trouble.
But it only applies between certain hours - from memory 06h00 and 20h00, so anyone with a car more then twenty years old - and I know a few in Paris, can get out to enjoy themselves.
And a warning - don't be taken in by the websites dressed up to look like the official one, that then rip you off. The full cost is €4.80.
Quentin
