To be honest.. I am stupid when it comes to things without youtube tutorials.. but i'll guess what happens.. In memory viewer, you replace the SSG82/MK23/M15A1/MP5 code with the weapon code provided??
And also.. what are the 00 00 00's for? In Astron51's weapon index codes, Astron only uses numbers like 01, 58, 96
Technically the weapon code is stored into a 4 bytes integer which means the code can be from 00 00 00 00 to FF FF FF FF. And of course 00 00 00 46 is the same as 46.