Ford Fiesta Metal Leather upholstery removal

Hello,

I had a very brief check prior to see if this topic had been raised before but couldn't see anything.

My problem is my ford fiesta metals heated seat pads are on there way out, I had the passenger seat out the other day to see if I could take the thing apart and repair myself. I was doing well until I got to the seat recline wheel adjuster at the side as this needs to come off so I can get the trim off and get access to the bolts needed to separate the back from the base of the seat. For the life of me I could not see a catch, something to push in and let the wheel pop off, from first impressions it looked like it just pushes on and catches round the mechanism but after sliding a flat head in there and trying to pry it off I started to doubt as despite a decent amount of force the thing didn't budge and I don't want to snap it off.

Anyone taken apart these seats (see image) and know what I'm missing here? 

Also due to not having the car long and the heated pads obviously needing a repair after opening the seat up so far I soon realised these metal seats are only heated on the bottom 😑

My intention now is the take out the old pads, install a new seat pad but also insert a back pad. Is it possible for me to solder the wires for the back and seat pads together and then solder these to the existing connection under the seat, would the extra pads be too much on the same 7.5amp fuse? The fuse diagram shows only one 7.5amp fuse for both heated seats (2 pads), would doubling the pads require a larger fuse now and would that mean I couldn't use the existing loom/wiring for the heated seat and have to add a new loom?

Thanks in advance