buschbob
.020 Over
The security bolts are quite soft so you can take a thin flat head screwdriver and tap a small slot in the bolt. Then you can unscrew them easily.
As idk mentioned, if you do not fit a headlight relay kit (a.k.a. the Eastern Beaver kit), you will be doing this again sometime in the future. http://easternbeaver.com/Main/Bike_Specific/Triumph/triumph.html
That sounds like an easier option then using a dremel, thanks. Would this "do" the same a the beaver kit? : http://www.ebay.com.au/itm/360461543240?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649