Thats a little vague. I'll help with what I can.
If you mean turn a custom jumpgate into a nomad one, you need to edit the archetype and loadout to nomad_gate.
If you mean unlock them in the game, you need to open initialworld.ini and edit it like this:
[locked_gates
locked_gate = 2926089285 ;St01_to_St02_hole ;St01_to_St02_hole
locked_gate = 2926433351 ;St01_to_St03_hole ;St01_to_St03_hole
locked_gate = 2460445762 ;St02_to_St01_hole ;St02_to_St01_hole
locked_gate = 2263303234 ;St03_to_St01_hole ;St03_to_St01_hole
npc_locked_gate = 2926089285 ;St01_to_St02_hole
npc_locked_gate = 2460445762 ;St02_to_St01_hole
npc_locked_gate = 2926433351 ;St01_to_St03_hole
npc_locked_gate = 2263303234 ;St03_to_St01_hole
All of the lines above need to be deleted.
If you are talking SP storyline, you need to check the
Freelancer Spoiler Forum
Hope that helps