I'm confused with installing gmstranded

Hi, guys im really confused with installing gmstranded. i would love an in depth (if thats possible with this question) tutorial on installing this gamemode. i have installed other gamemodes before, this time i dont know what im doing wrong. i downloaded the stranded 2.1.1 file and the 2.1.1 fix3 from gmod.org. i would love some help with extracting these were they go to ;-;! thx in advance!

bump ;o;