Well seen as I couldn't find one that explained it without pictures, I thought id have a go myself and take a few on the way.
1# remove the bigger rectangle
2# remove the rear ashtray and this plastic cover, just by pulling back and wiggling the clips free.
This will give you more room!
3#I missed a picture here sadly as I was distracted. But if you unbolt the bracket (thing that looks like a 3 fingered claw) from the armrest (if its attached) and unbolt the two nuts at the rear of the hole you've just opened up, you should be able to slide the bracket under the plastic and over the 3rd bolt that's just forward of this position. You will see it if you look through that rectangle piece you removed on top.
4#Once you've bolted the bracket in, you get a gauge of where the hole you need to cut will be. if you run your fingers under the plastic where you removed the ashtray from, you should feel like a rectangle shape lip going around.
You only need to really focus on the right side of this... Meaning you don't have to cut a hole the side of the armrest base.
5#put masking tape across the top and lay the armrest on top, as close as you can to where you think it will finally rest. draw around the armrest stand base with a pen/pencil and it should mark a small square, like this
You will need to cut this part out (but cut slightly less than this shape as you can always make the hole bigger but not smaller)
I used a small drill bit on a dremmel and I went around the whole box and filled it with holes.
6# I used a sanding bit to tidy the edges up a bit, its not really important as the base will cover this but feel free to spend time making it neat.
7# angle the armrest in like this
8# put the stand into the base and tighten the 13mm nut to secure it to the base. I also applied some locktight to just keep it secure.
9# refit the ashtray and plastic cover
(don't mind the marks and broken ashtray, these will be sorted)
10#Admire your handy work
I am also aware that the armrest is cloth and I have leather, im in the process of having this fixed haha!
Please understand I did this in my own car and with my own experiences, i don't intend anyone to copy what i did. This is purely trial and error on my own part.
I accept no liability for damage in your own vehicle if you copy this post.