To install the map you have to take the file Villa Richman 1.8.xml 
and to put it in the folder : C:\Program Files\Rockstar Games\Grand Theft Auto V\menyooStuff\Spooner

and drop the files that are in the objects list folder into the menyooStuff folder in the root folder of the game.

In game, to load the map, launch Menyoo with F8 then go to Spooner Mod then Manage Saved Files and load Villa Richman 1.8 !

enjoy !