Usage:
-skin [pure unit id]

Changes the skin of the selected unit(s) to that of the unit id. This includes voice set, model, name and icon, but doesn't include stats, abilities, etc.

Important to note that this doesn't use the unit id created by -codename, but rather a "pure" unit id. Instead of "custom_h008", you'd do just "h008", and instead of "footman", you'd do "hfoo".

Examples:
-skin hfoo
(Changes the skin to that of a footman)

-skin h008
(Changes the skin to that of a dwarf worker)