1. If you don't have a "luafiles/client/Shield Storage" folder, create one;

2. Create a file inside said folder (any name, as long as it's a .txt or .cfg file)

3. Inside the file, add one line for each shield you wanna add in this format (shield name, shield_constant, description, icon graphic, sfx_constant), parenthesis NOT included, example below:
   Amargeddon Shield,SH_ARMAGEDDON,No description,TVARICON,sfx_armasg
   
4. Boot up SRB2 and load the addon;

5. In the console, run the following command below replacing FILENAME with the name of the file you created (extension included):
   SS_SetCustomShieldList FILENAME
   
6. Afterwards, still in the console, run the SS_ReloadShieldList command for your changes to take effect;

7. Play the game, have fun.