You don't. Soak them in your bathtub in warm dish water. After an hour or so scrub them down and remove the flocking so you never have to worry about a finger print or scuff again. :mrgreen:
There are flocking products available for inside of glove boxes, those fuzzy garage door opener holders and all those other compound fuzzy bits found on so many cars from the 70s and 80s. Sadly I have not read here or know of anyone that has achieved a decent colour match when used on the pillar trims. There are a few existing threads with products folks have tried... but they usually revert back to zero maintenance and ease of cleaning. Remember that only the early years had the flocked pillar trims. LR got smart after many wrranty replacements and complaints and in the later years and they were the same colour keyed plastic trims, but textured. I assume you have a GEMS P38. Cleaning those up will give you a perfectly match trim that easily wipes clean with a paper towel and your favourite glass cleaner. Unless you are going to have your Rover in judged events no body will ever notice.
I kind of like the flocked look and have been looking into this issue for a while. There is an outfit like Toad Hall stated that can provide a refreshed look for the pillar trim. I have a spare set of pillars that I grabbed from a pick n pull. I'll report back how it turned out.