Instructions
 
Connect your Action Replay card to your computer via the USB card that came with the device. 
Open your "Action Replay Code Manager" software from the start menu or the desktop icon. 
Right-click the "My Codelists" panel at the bottom of the screen. A panel will appear, similar to if you right-clicked on the desktop. 
Click "Add new code." A new window will appear. 
Type the "Wild Pokemon Modifier" cheat in the window: 
02064ec8 47104a00 
02064ecc 02000031 
94000130 fcfe0200 
02066db8 47084900 
02066dbc 02000001 
d2000000 00000000 
94000130 fcfe0100 
02066db8 95019000 
02066dbc 90022000 
d2000000 00000000 
62000000 95019000 
e2000000 0000004c 
95019000 90022000 
1c28b40d f0684907 
1c01fd4d 2901bc0d 
4902d101 49024708 
00004708 02066dc1 
02066d9f 00000000 
95019000 69384a04 
98046010 4b019a09 
00004718 02064ed1 
0200002c 00000000 
d2000000 00000000 
Save the changes by clicking "Save" from the "File" options on the top toolbar. The changes will automatically be made to your Action Replay card. To activate the cheat inside the game, press "R" and "A" once inside the game. To deactivate the cheat, press "L" and "A" on the trainer screen from the game's menu.