Customizing
Kitbashing is a dire-sounding process that does not involve hammers and weirdly-named Jedi Knights that die easily (wait a minute...)
(WHAM!) (WHAM!) (WHAM!)
Ah. Kitbashing involves combining or modifying parts from one or more kits to make a custom model. The term has been extended to apply to models and toys such as Transformers that are not sold as kits. Kitbashing is sometimes called customizing.
The purpose of a kitbash is to obtain something that can't be bought, to improve something that can, or simply to engage in a refreshing exercise of creativity.
Kitbashing may be as simple as repainting a small detail. It may also be quite extensive, resulting in a product that in no way resembles any of its original sources. The derived parts are frequently augmented by scratchbuilt ones, and any part from any source, whether it is a Lego brick, a plastic tank tread, or a Barbie doll head, can be part of a kitbash.