If the template contains things you are proud of (i.e want to keep) then look in the TOOLS / OPTIONS / FILE LOCATIONS tab where your active version of NORMAL.DOT is located, although you can't read it! (Good one, Microsoft.) So, highlight the template entry and click modify to see the full path. Note it and close the box as you don't want to change this. You can then drill down to the file in the Open box (having selected .DOT not .DOC!) and make the necessary changes.
If, on the other hand , you just want to start from scratch, the use Explorer's FIND facility to locate all instances of NORMAL.DOT and delete them. When you next open Word, a virgin copy of Normal.dot will be automatically created, but it will probably use american default settings such as letter not A4 etc., so you may still need to customise it in the UK.