This is just a quick guide on how the solve the problem, I will add that these units are also found on the X jag, Citreon Picasso and the MG z cars if you need spares cheaper than under the Mazda stamp.
I would also check that the bulb holder is seated correct and not letting any water past.
First make sure the handbrake is on and the wheels are choked, there is no need to remove a wheel for this but you will be rolling on a floor


You will need a Phillips screw driver ,small medium ratchet with extensions with a 10mm socket and a 8mm socket a torch will help also,and a tin of penetrating oil.
Crack and remove the 10mm head bolt, you may find that this has not been removed for some time and puts up a fight(we will win) this is where the easit oil comes in as it will crack it , if it feels like it will snap spray it and re-tighten and so on undo /re-tighten ,back and forth spraying as you go, slowly slowly catchy monkey, rebuild everything back up with copper slip

If they do snap ? then give Andrew a ring at Autolink for some of his 12mm head self tappers so you will never have the same problem ever again

The trim clips are a Phillips head and just turn the center bit out which will only come out so far and then just remove the whole clip you might need to spray these also after the years of crap in them.
Next it is under neath and remove the 3 x self tapper 8mm and Phillips head bolts (choice is yours what you remove them with)
3 x 8mm and Phillips head screws removed....
Next you will be hit by these trim clips....
Push the center bit in and you will hear it click and then remove the whole thing....
You may hit these trim clips ? if so just unscrew the center all the way out and remove the body,on rebuild fit the body in place first and just push the center section back in place there is no need to screw it back in...
Then just remove the forward wheel arch liner...
You should now be able to see the fog/spot light/lamp unit....
Unplugged the electrics from it.....
Now you need the unscrew the 3 x Phillip head screws that hold the unit in place.....
Once they are all removed ( be carefull that it does not fall to the floor and smash)...
Find the aim adjuster....
And pop it out.....
Look for the locking tabs on either side....
Lift them up gently so not to snap them and pull the body free from the tab....
Do the same thing on the other side....
And it should now pull apart.....
If damp is getting past this more than likely is the reason why....
Remove it and turn it over so it will make a better seal......
If you look close enough you should see the difference on the blades of the seal between the two pics.....
Job done, refit as removed .
M-m