New plug on surge proected extension

[mal165]

Hi, I have a surge protected 6 way extension lead and would like to shorten the length of the mains lead to it.
There is a manufactures label attached saying that a new plug should not be fitted, if cable is damaged
Am I correct in assuming this is to do with the mains lead being screened and would therefore appreciate advice on what would be involved in changing the plug.
Thanks in anticipation.

 

[Wayners]

Probably a warranty thing as when the surge protector blows you would contact company for free replacement.
Maybe swapping plug would open up possibility of incompetence shorting out the surge protection. Maybe?