PakScape

PakScape is a PAK and PK3 explorer/creator. It doubles as a ZIP explorer/creator
because PK3 files are really ZIP files.

The PAK file formats supported are the formats used by games based on the Quake, Quake II, and Quake III engines. 
The games based on those engines include majorly popular games such as: Half-Life/Counter-Strike, Soldier of Fortune (1,2), Daikatana, Return To Castle Wolfenstein, Jedi Knight 2: Jedi Outcast. Theres alot more games than that but too many to list.

Make a PK3/PAK file
edit a PK3/PAK file
open a PK3/PAK file
Save a PK3/PAK file

I hope it will help you making a skin are a map

GreetingS walsie