Remove the seats. Wire brush the metal and paint with Rustoleum.
@Rover Range -
I am doing it!
Like others have noted here, I have also been disappointed over the years by all the corrosion under the seats. I know that I had a lot of brown rust already in 2012 - only two years after manufacture. While the rust never got worse...it seems unsightly on such a nice truck (did they forget to paint this or what?).
So with my rebuild...it is time to do something about it!
This is therefore part of the ongoing services and also related to the floor sound deadening and carpet cleaning (in cabin work).
So far, so good and I am making comments about how things are progressing herein other threads like
Tribe, New question and thread here - Does anyone have any experience in sound deadening and thermal insulating their interior flooring? This job requires pulling the seats out and pulling the carpet up to get underneath all that and see the flooring (to include footwells). Here are a few...
www.landroverworld.org
As
@Rover Range notes - best to just pull all the seats out and then clean things up and repaint as necessary.