If you have a console ingame just type in: bind h "sm_tripmine"
Copy and paste that. And every time u press h you will spawn 1 tripmine. But u only have 3 mines every round. If you dont have a console im gonna tell you how to get one.
Click on steam so you get to the "steam page" . Go to my games and right click on Counter-Strike source. Select properties and then press "set launch options" In there type in -console NOT console.... it shoul be -console . Exactly like that. Then press ok and launch counter-strike source. And ur supposed to have a console. In the console type bind h "sm_tripmine" (cope and paste it)
And ur done. Press h to spawn a tripmine. Tell me if u didnt get it Cuz this is really easy for me so i might explain it badly.. Just ask if u dont get it to work 
