Either polish them off, or get another can that doesn't have it on.
I only say that because I got caught by a bikesafe stop where EVERY bike was pulled in, and a VOSA bloke went over each bike with a fine tooth comb for illegal parts.
Mine had an ART can fitted with those fateful words written on it "not for road use". The cops issued me with some kind of road injunction notice (can't remember the correct name for it) which meant take the bike home immediately, and the only journey it can undertake is to an MOT station where it has to be fully re-MOT'd.
I did exactly that. Took it home and got a new ticket for it, wen to the cop shop and had the ticket cancelled. I then went on tour in Canada for 3 months, returning home to find a court summons sat waiting for me. The cops hadn't sorted the ticket in time or some shit like that, and a summons is issued.
I went to court and stated my case that I'd done everything that had been asked of me. The magistrates said they didn't have a clue why I was here in that case, but since I was here, I should have a 12 month behavioural notice, should I get in trouble again this would be taken into account, and don't do it again!!!
In my experience buddy, it just aint worth it! Get a road legal can.