I fitted one of these a couple of weeks ago, the video left me confused too so I called fast and spoke to Fabien, he was super helpful and explained that you don’t need to remove the lowers, they did that to show the bleed process as it was more convenient for the video, he explained that you should bleed the fork.
Fitting the kit was super easy, unscrew top up oil, fit new cartridge, and bleed.
I ordered one of these ( eBay 191814665996 ) used an inch of pipe on a syringe like in the video, I ordered the same Rockshox 5wt oil that came in my new Revelations ( eBay 283904752489 ) to top up the cartridge, before refitting I checked the oil level in the fork, and in the syringe, my cart definitely took a bit more oil while cycling the forks and twirling the dials.
He told me the base settings where 14 clicks each dial.
Op is probably sorted now but I thought I’d add this for anyone searching the net for info.