Close the SDK.
SteamApps\common\SourceSDK\bin\source2007\bin\GameConfig.txt:
"Configs"
{
"Games"
{
"GoldenEye: Source"
{
"GameDir" "C:\Program Files (x86)\Steam\steamapps\sourcemods\gesource"
"hammer"
{
"GameData0" "C:\Program Files (x86)\Steam\SteamApps\sourcemods\gesource\goldeneye.fgd"
"GameData1" "C:\Program Files (x86)\Steam\steamapps\common\SourceSDK\bin\source2007\bin\base.fgd"
"TextureFormat" "5"
"MapFormat" "4"
"DefaultTextureScale" "0.250000"
"DefaultLightmapScale" "8"
"GameExe" "C:\Program Files (x86)\Steam\steamapps\common\Source SDK Base 2007\hl2.exe"
"DefaultSolidEntity" "func_detail"
"DefaultPointEntity" "info_player_teamspawn"
"BSP" "C:\Program Files (x86)\Steam\steamapps\common\SourceSDK\bin\source2007\bin\vbsp.exe"
"Vis" "C:\Program Files (x86)\Steam\steamapps\common\SourceSDK\bin\source2007\bin\vvis.exe"
"Light" "C:\Program Files (x86)\Steam\steamapps\common\SourceSDK\bin\source2007\bin\vrad.exe"
"GameExeDir" "C:\Program Files (x86)\Steam\steamapps\common\Source SDK Base 2007"
"MapDir" "C:\Program Files (x86)\Steam\steamapps\common\"
"BSPDir" "C:\Program Files (x86)\Steam\SteamApps\sourcemods\gesource\maps"
"CordonTexture" "tools\toolsskybox"
"MaterialExcludeCount" "0"
}
}
}
"SDKVersion" "3"
}
Then load Hammer and change the game paths/settings as needed.