Right lets have a go at this! i'm useless at writing guides,but here goes!
Firstly these are torx bits and you only need a t30 one to do this,available from halfords!
Then take off your remaining wiper,and the plastic tray,it pops off! (No pics sorry didn't want to risk another £70 on mine
)
Then pull off the rubber seal (if you haven't to get the tray off) next undo the 2 little black metal screws either side of the metal panel,as shown by my finger in this pic.
Then grab the metal lip of the firewall and wiggle it out,see pic (It is coming away there but its not very clear!
Next undo the 2 bolts holding the wiper linkage in,again my fingers pointing to one,the others by the spindle itself (second pic)! and the motor assembly should now come out complete!
And then with the motor out,you need to undo the three bolts holding the arm in (pictured but easier with the motor out) and swap for the new linkage.
And then refitting is the reversal of removal,the only slight tricky bit is the motor has a locating lug which is a bit of a fiddle to get into the hole before bolting it in,but you'll see where it needs to go!
So good luck with it,if i can
help anymore,give me a shout.
Another Paul