Took mine out the other day, was a rare pita, wasnt even at fault so its back in now lol.
You need to remove wiper arms, just some small nuts, 10mm iirc
Then remove the plastic underneath the windscreen, just some plastic fasteners holding them in
Disconnect the wiper motor with the connector on the front of it
Remove wiper motor, 2 bolts at each end iirc, and a locating pin at the back which you need to make sure it is in when you put it back together
Then you should see a small square box, this is attached with 2 nuts, undo the nuts
Pull alarm out, undo 3 small screws on top, open up, remove connector
Reverse then to put it all back together