After collecting the RLS-7, you will cross a footbridge that overlooks a highway bridge and has enemy soldiers fighting giant mutant spiders. Use the TDM on the other side of the footbridge to revert the lockers in the room. Then, find the note inside one of them that reads: "My neighbor, he is pain in my assholes. I get a bear made of fur, he must get a bear made of fur. I get a can of meat, he must get a can of meat. I get a E99 technologies... he cannot afford. Great success!"
Board the freighter to come across a weapons locker next to a watertight door. A control panel to open the next door will also be in that small room. Before you operate the control panel, equip the Dethex Launcher and use the secondary function to put a guided grenade (press X to jump) through the grate maze in the wall and floor of the room. Then, use the bomb to blow open the locked watertight door. Inside, you can get a weapon tech pick-up and revert a message for this trophy.
Right after upgrading the TMD to its final level (where it does not use TMD Energy for all attacks), break the vent behind the upgrade machine. The crawlspace leads to this easter egg and some other items.