can someone plz help me with HEX editor!!!

[t3chy0]

i just got into this stuff but my friend couldnt help me cause he had to go do something and said ask around so this is waht im doing. Im trying to get weapons to shoot out vehicles. Now i got the offsets and what not and the hex program opened with the cache003.map bg file open with it. My AIM sn is outtrigger888 if someone could help me really quick that would be awsome, thanks...