This is just a sample, find the ship you want in the loadout file. Just don't add more than the ship can hold with out changing the cargo hold or it will cause a crash. See bold area:

[Loadout
nickname = gd_gm_ku_freighter_loadout02
archetype = ku_freighter
equip = ge_kfr_engine_01
equip = npc_shield01_mark06, HpShield01
equip = infinite_power
equip = ge_s_scanner_02
equip = ge_s_tractor_01
equip = ge_s_thruster_01, HpThruster01
equip = armor_scale_4
equip = gd_gm_gun01_mark01, HpWeapon01
equip = gd_gm_gun01_mark01, HpWeapon02
equip = gd_gm_turret01_mark01, HpTurret01
equip = gd_gm_turret01_mark01, HpTurret02
equip = gd_gm_turret01_mark01, HpTurret03
equip = gd_gm_turret01_mark01, HpTurret04
equip = gd_gm_turret01_mark01, HpTurret05
equip = gd_gm_turret01_mark01, HpTurret06
equip = ge_s_cm_01, HpCM01
cargo = ge_s_cm_01_ammo, 20 ;Change the cargo it is carrying
equip = LargeWhiteSpecial, HpHeadlight
equip = SlowSmallGreen, HpRunningLight01
equip = SlowSmallGreen, HpRunningLight02
equip = SlowSmallGreen, HpRunningLight03
equip = SlowSmallGreen, HpRunningLight04
equip = SlowSmallGreen, HpRunningLight05
equip = SlowSmallGreen, HpRunningLight06
equip = SlowSmallGreen, HpRunningLight07
equip = SlowSmallGreen, HpRunningLight08
equip = SlowSmallGreen, HpRunningLight09
equip = SlowSmallGreen, HpRunningLight10
equip = SlowSmallGreen, HpRunningLight11
equip = SlowSmallGreen, HpRunningLight12
equip = contrail01, HpContrail01
equip = contrail01, HpContrail02
equip = DockingLightRedSmall, HpDockLight01
equip = DockingLightRedSmall, HpDockLight02

Thanks alot!
But how can i open the loadout files? It seems to require some decode software or similar.
Also... How do i know what designation is the one to change? Is there a table or somthing?

Actually, it's found in the lootprops.ini file. Here is a typical entry:

[mLootProps
nickname = commodity_boron
drop_properties = 100, 0, 3333, 1, 150, 150

I'm not really exactly sure of all the numbers here, but here is basically what they mean: the first number is the percent chance of loot dropping (in this case 100%)

The last 2 numbers (150, 150) determine the MAX amount of cargo that will be dropped when you blow up the transport or it's cargo pod. So, despite it saying 79,999 - only a max of 150 will come out as loot when you blow up the ship.

The next 2 numbers (0, 3333) determine the range of how much loot drops, and are related to the last two numbers (150). So between 1 and 150 cargo will drop. The numbers (0, 3333) have to do with your level, but I'm not sure how it is calculated. If you are say level 2, when you shoot a transport, only 2 or 3 cargo will drop. But if you are level 20, then mabye 45 will drop. And if you are level 30, then 150 drops.

So, you would need to change the last 2 numbers for the MAX amount of cargo you want to drop, and change the 2nd and 3rd numbers to determine what percent of the max number to drop depending on your level.

- Wasabe

To answer your other question, you need to download the Freelancer SDK, it's basically a complete set of the decoded ini files.