As Lifson explains, and Michael Roberts explains at The Balance Careers here, on Day 30 of the shutdown, a clause is triggered in these federal employment contracts that enables RIF.  The Office of Personnel Management oversees the RIF process.

A downsizing plan must be presented to OMB on Day 31.  Trump's team needs to act fast.  The plan must include all of the people who just sit around texting each other about their next leak to MSNBC, or planning their next protest march in a pink hat.  It will take another 30 days to implement the plan.  Roughly 800,000 federal employees could be permanently removed under this plan, with an annual savings of roughly $80 billion in salaries alone.  Including the pensions; the government vehicles; and the rented office space, furniture, and equipment, it could be $150 billion.

In particular, removing the SES employees and their hefty salaries represents a huge savings.  After the massive RIF, Trump could go ahead with Plan B, declare an emergency, and send that order to the Corps of Engineers.  The Democratic Party will be faced with a Hobson's choice: lose the Latino vote, or lose the Deep State.  I suspect that when presented with this possibility, Chuckie and Nancy will immediately cave in (they aren't that stupid).

At that point, Trump should raise the stakes.  "Approve all of my judicial nominees immediately, or the shutdown continues, and the RIF takes effect.  Then I declare an emergency, and I get my border wall anyway

https://www.americanthinker.com/articles/2019/01/trump_puts_schumer_and_pelosi_in_a_brilliant_vise_grip.html

Who is Donald J Trump's current chief of staff. Mick Mulvaney. Where was Mick before COS position? OMB director. Now do you see the Plan?

Brilliant [D5] move on [DS] Mr President playing that 3D Chess again. KHASHOGGI style.

WWG1WGA