Do you like the gravity as you can see in this screenshot? I am here with the tutorial!
Openup _zombiemode and search for this:

onPlayerConnect_clientDvars
you will see this:

self SetClientDvars( "cg_deadChatWithDead", "1",
        "cg_deadChatWithTeam", "1",
        "cg_deadHearTeamLiving", "1",
        "cg_deadHearAllLiving", "1",
        "cg_everyoneHearsEveryone", "1",
        "compass", "0",
        "hud_showStance", "0",
        "cg_thirdPerson", "0",
        "cg_fov", "65",
        "cg_thirdPersonAngle", "0",
        "ammoCounterHide", "0",
        "miniscoreboardhide", "0",
        "ui_hud_hardcore", "0" );

change it to this:

self SetClientDvars( "cg_deadChatWithDead", "1",
        "cg_deadChatWithTeam", "1",
        "cg_deadHearTeamLiving", "1",
        "cg_deadHearAllLiving", "1",
        "cg_everyoneHearsEveryone", "1",
        "compass", "0",
        // gravity
        "phys_gravity", "0", // Zombie gravity
        "g_gravity", "80", // Player gravity
        "ragdoll_max_life", "500000", // Life time of dead bodies flying around in the air in milliseconds
        // gravity
        "hud_showStance", "0",
        "cg_thirdPerson", "0",
        "cg_fov", "65",
        "cg_thirdPersonAngle", "0",
        "ammoCounterHide", "0",
        "miniscoreboardhide", "0",
        "ui_hud_hardcore", "0" );

After you changed that, build the mod and you're done!
Have fun testing! (If this tutorial is already on the forum you have my sorry)

No i don't like the gravity shown in your screenshot. I am not impressed btw!

No i don't like the gravity shown in your screenshot. I am not impressed btw!

Jokes on you!

Jokes on you!

What is?