if IS you split the fairing not sure for the other models
For the IS you can access them by turning the bars to the lock and it's a simple removal.
Instructions are on ShopTalk
http://www.valkyrieriders.com/shoptalk/interstateheadlight.htmIt's not as bad as they make it seem. Took me half an hour, and that includes the trip to get the new bulbs before I started. No tools required.
As far as the Standard / Tourer my memory is a bit fuzzy, but as I recall there are two #2 phillips screws at the bottom of the headlight bucket, remove those and the ring and lens should pop right off and the bulb is then accessible from the back.