Get Halo Custom Edition and install it (you need valid CD key though, hope you own Halo PC!) (http://hce.halomaps.org/?fid=410)
Patch it to 1.10 (https://www.bungie.net/en/Forums/Post/64943622)

Download the restoration single player maps and “UI map” (https://www.reddit.com/r/HaloCERefined/comments/9l9ujl/downloads/)
Place these into your [Halo CE location]maps, including the UI.map, overwriting the old one.
(Ending vids aren’t necessary, if you get them, they go to game root folder.)

Get Chimera (https://opencarnage.net/index.php?/topic/6916-chimera-build-49/)
It is a single dll-file that goes into [Halo CE location]controls.

Start the game, and open console (key should be the one left from 1), input following commands:
chimera_interpolate 9
chimera_fov_fix 1
chimera_vfov 55.41
chimera_uncap_cinematic 1