Ensure that you are using the original default.ide for the mod to work.

First, import new gun@handgun.wad to pc\anim.img with SparkIV or OpenIV.

Second, with SparkIV, export your WEAPONS.ivaud from resident.rpf (find it in
pc\audio\Sfx). Open the WEAPONS.ivaud with GTA IV-aud and import all sound files
to here (match the names):

PISTOL_SHOT1_L
PISTOL_SHOT1_R
PISTOL_SHOT2

Save once done and import back to resident.rpf, Save and close.

Now install the new WeaponInfo to Pistol line below:

	<weapon type="PISTOL">
		<data slot="HANDGUN" firetype="INSTANT_HIT" damagetype="BULLET" group="PISTOL_SMALL" targetrange="75.0" weaponrange="250" clipsize="33" ammomax="363" timebetweenshots="333">
			<damage base="20" networkplayermod="3.0" networkpedmod="1.0"/>
			<physics force="20.0"/>
			<reload time="2000" fasttime="2000" crouchtime="2000"/>

			<aiming accuracy="1.0" accuracyTime="1500.0">
				<offset         x="0.15" y="1.0" z="0.55"/>
				<crouchedoffset x="0.2"  y="1.0" z="0.05"/>
				<reticule standing="0.65" ducked="0.55" scale="0.3"/>
			</aiming>

			<pickup regentime="120000" ammoonstreet="10"/>

			<controller>
				<rumble duration="110" intensity="0.02"/>
			</controller>

			<flags>
				<flag>GUN</flag>
				<flag>CAN_AIM</flag>
				<flag>CAN_FREE_AIM</flag>
				<flag>ANIM_RELOAD</flag>
				<flag>ANIM_CROUCH_FIRE</flag>
			</flags>
		</data>

		<assets model="w_glock">
			<anim group="gun@handgun" meleegroup1="firearm_core">
				<rates firerate="1" blindfirerate="1.8"/>
			</anim>

			<effects>
				<muzzle fx="muz_pistol_small"/>
				<shell fx="weap_ejected_pistol"/>
			</effects>
		</assets>
	</weapon>