Do you already have the fog lamps mounted now? If so, it should be a doddle, buy the LED reflector inserts, put them in there and use the cables already present (well, there is one positive wire with current and the other you can just attach to the housing on the inside to ground it). Haven't done it, but I did mount a set of fog lights a couple of months ago (my bike is from back when Triumph were extra greedy and sold those as an addon).
There is also a positive (power) wire available inside the headlight that is connected to that switch but only if you have the sub-harness that plugs into the existing little connector on the stock harness, under the tank. So if you don't have the stock fog lights already, you probably want to buy that bit of cable and then figure out how to get cables from there into whatever lamp housings you want to mount.
Instructions for the original fog light kit, shows clearly how the power cables are connected and whatnot:
http://www.triumphinstructions.com/ProdDocs/A9938085-EN.pdf
The sub-harness is available at World of Triumph for £6.90 and no doubt other places:
http://www.worldoftriumph.com/trium...ck_01=&block_02=100053709-1-2&block_03=610510
Hmm, also need a relay I guess and uh I may be missing something with regards to the indicators... oh well.
But (without having tried, so there may be pitfalls I'm not aware of) if you have the stock lamps on there already, it should be very nearly effortless - open the fog lights, take out the reflector, put in the LED reflector and connect the wires, assuming we're talking about something like Truck-lite Phase 7 4.5 inch driving lights.
The LED's are more directional forward than the stock lamps though, so from an angle you may wind up being somewhat
less visible. There are other options for more lamps too, Clearwater for instance, in addition to the ones already mentioned.