It’s simple. Go to the Iwar2 folder on your harddrive, then go to Mods > MS_Mod_Ships > Sims > Ships > Player and open up Storm_Petrel.INI in your notepad.
Once there, copy this:
template[16]=ini:/subsims/mountpoints/capsule_drive
And paste it right after this:
template[15]=ini:/subsims/mountpoints/light_cannon_mount
null[15]=hardpoint_leftwing
It’s out of order i know, but it’s simple and easy to do, and more importantly, it works.
Save, and enjoy your Storm Petrel with a capsule drive. 😀