How do I remove glow in the dark paint from my walls?
You can try with soapy water.  But - having removed a lot of paint, what you're hoping for is probably impossible.  Even if you get the glow-in-the-dark stuff off, doing so will roughen up the underlying paint to the point that repainting is necessary.  

You are stuck repainting, the question is whether you'd rather DIY or pay the landlord to do it.   First, I'd confer with the landlord about his plans and see if you can come up with a compromise.  Landlords don't make their money chiseling tenants out of their deposits.**  They make their money having the unit rented continuously, and uneventfully, with the least downtime and maintenance expense.   So see what can be worked out.

You'd definitely want a coat of quality primer like Kilz to keep the GitD paint from printing through the new topcoat.  Scuff-sand the whole wall (just a few swishes with a Scotchbrite pad to knock the gloss off, especially over the GitD paint, paint does not stick to gloss); wipedown with TSP substitute to remove chemical contaminants (body oils etc.); then roll and brush on the primer.  It's not a huge job, the biggest part of it is protecting your possessions and the carpet and window trim.  If the carpet is scheduled for replacement, it's good to know that. 

** In fact they usually lose money seizing a tenant's deposit. Their cost of doing the work is far beyond the deposit, and beyond any amount they could ever hope to collect from a typical tenant, even if they went to court.  So they just say "heck with it" and move on.