I bought a set while ago for my 1997 Ford SHO and they had tinted glass on them and the lighting sucked horribly. You'd be better of getting Sylvania SilverStars or Cool Blue if you want better light output. But, if you want really xenons, then check out that open group buy of Prolumen kits in Classifieds forum.
OK, look In the engine compartment at the top of the headlight bucket. If its an early New beetle there will be a suit case latch that needs to be unclipped. Next, get two large screw drivers. There is a plastic lever sticking up that is attatched to the slider. In front of the lever there is a small rectangele lock. Push down slightly on the lock, while Pushing the slide lever down towards the ground. If everything goes right the headlight will pop out, as the slide moves about three inches, Usualy it sticks thoughe. It may help to push on the back of the headlight with a long screwdriver while working the slider. once its part way out you can pull on the front of the headlight while working the slider, don't pull on the lens too hard, it may come loose. If the slider breaks the later ones are available & pretty easy to replace. The early ones are no longer available, (last I knew) & you will also have to replace the bucket. Compare the parts closely before leaving the parts dept., as they all look similar. Also don't bend the bucket tin or lock slide won't work properly. The plastic is very fragile, especialy after baking in the engine compartment a few years. It helps to soak everything in silicone spray before going back together.