Hexadecimal, unlike our normal decimal system, is based off the powers of sixteen. Decimal, our normal number system, is based off the powers of ten. For example, every digit you go across on a decimal system multiplies the previous base number by ten.
1, 10, 100, 1000, 10000, 100000, 1000000
The Hexadecimal system instead goes by the powers of 16.
1, 16, 256, etc
Where the decimal system has 0-9 for the amount of a base number, the hex system has 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F where 0 is 0 (duh) and F is 15.
Now for hexadecimal numbers. A hexadecimal number will look like this: 1B 2F 30. Each 2 digits are separated by a space. Now can you convert that number to decimal? the number is the base number (1, 16, 256, etc) multiplied by the amount (0-9,A-F). Convert using multiplication, and you get a nice round decimal.
Packets are what is sent from one computer to another in terms of data. They are used for various purposes, such as pinging and telling the computer what happened. The gist of this is you can edit packets to conform to your values.
In this I will assume you know basic hexadecimal.
1.) Download a packet editing program (I use WPE Pro)
2.) Start it up after installation.
3.) Open up a program with access to the internet (IExplorer is good)
4.) Go to select process in the program, and select the program you want to monitor.
5.) Press the monitor button to record packets sent to and out of your computer.
6.) Stop after a little while, and view the packet log.
Here is the tedious part. You have to search through the packet log for packets with similar values, but that are different in a few ways. For example, I could have two packets that say:
00 2A 56 00
00 2A 42 01
Now these packets are very similar. If I wanted to make it so I would change the 56 packet to the 42 packet, I would create a filter. In the filter I would have the values to be searched for, and the values that are modified. After that I would enable the filter and set the program to monitor. That makes it so any packets coming into or going out of my computer are changed to the value I wanted.