unfortunately, being as yours is LHD i'd imagine access to the "silver thing" as described above is going to be harder than just pulling the glovebox out, (as yours is on the wrong side) you may be able to get at it by removing the lower centre console trim (remove the little plastic covers to find the screws)
are you getting nothing at all, or very little air to the windscreen? if its a little, the silver thing might be blocked, there is some how-to's in this part of the mk1/2 mondeo forum, click "search" first and you can change where you "search" to "this forum" and use "vacuum" as your search word, and you'll only get results from this forum.