Very simple to get, just complete activities that aid the Freelancers, go to Fort Tarsis and head to the Freelancer Enclave, head to where Yarrow is standing most of the time, interact with the contract board and go complete the contract, rinse and repeat until you reach 3000/3000 on Freelancer Loyalty 3, the achievement should pop,
UPDATE 1
GLITCHED as of 05/03/19 - This achievement is unlocking for some people but not others, so just be aware of that, Bioware are aware of the issue.
UPDATE 2
As of the 23/04/19 this achievement appears to have been patched by the latest update to Anthem, thanks to NoblestSteed and MarkimHenrique for their comments.