First thing to do is verify what bulb you have in your wingtip. Can't tell for certain from the picture, but it looks to me like it might be a PAR 36 bulb. Commonly used and easily replaced with units from a variety of sources, aviation and non-aviation. If it is a PAR 36 bulb the replacement is a simple task. Search with google: "PAR 36 replacement site:vansairforce.net" and you will find all kinds of suggestions.