this is a HD quality NRG 900F mod fot gta sa and it replaces FCR 900 to install it you must have an img tool(the best option is- alci's img tool) and follow the steps to install...
1.download and extract it to a safe location
2.once extracted, open your img tool
3.using the img tool open gta3.img located in the models folder in your gta sa directory
4.import the two files(.ddf and .txd)to gta3.img and then click rebuild archive and wait a while till it finished rebuilding and open the game to see the conversion

 and this is my first mod so try to be nice and if you find any problem please report it to my personal e-mail ID...