first one - there's a flat bar that goes from the end of the cable to the large circle thing on the motor, at the circle end of that bar, there's a semi circlular 'E' shaped clip on holding it down (at the bottom right of your picture), use a screwdriver to prise it off, then the bar will lift off and you can get the cable out. When you go to remove the wheelboxes and the main cable enclosure, there's a trick to it, you need to rotate the bottom of the whole assembly upwards - kinda roll the wheelboxes out of the panel, they won't come straight down. Don't try seperating the wheelboxes from the cable enclosure while it's in the car, that'll cause a world of trouble

second one - there should be a small clip right above that big nut, that goes up into the arm - it's missing from yours by the looks, I'd just go around the base of the arm with a wide bladed flat screwdriver, prising it away from that big nut - it'll come off without wrecking it, they're pretty tough. There's a spline that's meant to stay on the end of the wheelbox, it may come off, but don't stress if it does, wheelboxes are easy enough to get hold of

if you clean the grease and crap away from the clip you will hopefully be able to see it doesnt go all the way around. The side where theres an opening is the side that "has an opening" so you need to push the clip away from the shaft and that opening will go either side of the shaft

Often the arms corrode a bit onto the splines, if so you may need to hold it as I said above and twist a flat screwdriver under it.

The `clip' is a spring, it will spring outwards as you pull the arm off. it's not a circlip or anything.

BTW I reckon the Haynes has to be the most shocking manual ever, for Oz Minis.. it may be OK if you drive a Rover.

Haynes are so good- my new one for the AU Ford doesn't even say what sparkplugs to use, or plug gap. Does show a pic how to adjust `em though. Muppets..