Hi Terri,
The gilding of champleve can be done with 2 methods, Mercury gilding (water gilding) and Electro gilding.
Mercury gilding is done by an amalgam of gold and mercury, which mixed with water is painted on the metal and then subjected to heat high enough to drive off the mercury, leaving the gold attached to the metal.
Electric gilding is done by the use of an electric battery, and is practically the same as gold plating (electro plating.) with a few practical modifications.
You can read more about how the two methods are done on these sites.
There is a lot of information online, if you search for Mercury gilding, water gilding or electric gilding + how to.
I hope this answers your answer, if not let me know, and I will dig deaper.