When I pulled mine. I slipped a small butter knife in between the bottle and shroud. Apply very little pressure against the bottle, while pulling the bottle up, that should disengage the tangs. Be very gentle. I would not try removing it if it is really cold out. Might crack the plastic.
Took me a while to figure it as well.
2003 Ram 1500 SLT,4.7,4x4 L.B. 4.10 motive gears,auburn LSD,PML rear diff cover,3715 super chip,airaid M.I.T. & E.A.A. dry air filter,flexalite electric fan B.M.180 extreme with moe's fan shroud delete kit,hemi radiator(spectra CU 2813)jet 180*stat, JBA shorty headers,homebrew power wire,aeroforce interceptor scan gauge,sonnex line pressure booster.