the cover would need to be drilled 25mm i think. just get a hole saw from B&Q for about £5.
As for MOT issues and legality, I personally have HID's installed on my last 3 cars so about 5 years and have never had an issue with MOT,s.
To be legal your lights need to have projector lenses, have headlight washers installed and be self levelling.
The only thing your car hasn't got is self levelling lights. The most important thing to have is projector lenses so that you don't blind other motorists because projectors have a clear cut off. You can see it if you park up against a wall with your lights on, It looks like this ---/ ---/
A lot of members have HID's installed and i can honestly say that i have never heard one issue with regards to MOT's or Police interest.
The headlights used in that video are the old reflector lense type and not projector lenses.
The only difference between your lights and the optional xenon lights for the accord are self levelling motors. Unless you drive round with bricks in the boot and are incapable of using the beam adjustment wheel if you ever tow a caravan then you should have absolutely no problems.