Download Unreal Gold Patch 227i from:
https://www.oldunreal.com/downloads/unreal/oldunreal-patches/.

Just scroll down. There are green coloured links. Remember, choose: UnrealGoldPatch227i.7z

Unpack it and install it to Unreal directory - default is:
C:\Program Files (x86)\Steam\steamapps\common\Unreal Gold.

There is also more recent patch 227j but it will not work with DX11 renderer so until renderer update we willl stick to 227i. More info in this forum topic: https://www.oldunreal.com/phpBB3/viewtopic.php?p=100771#p100771

"The DirectX 11 renderer is not compatible with Unreal 227j. The renderer is a project made by a 3rd party developer for Unreal 227i. I don't know if this developer will or can update it for Unreal 227j support. For now you have to choose to either use Unreal 227i with DirectX 11 or use Unreal 227j with xOpenGL or DirectX9."

Download High-Resolution Unreal Skins (UnrealHD v3.1 Full) from https://www.moddb.com/mods/high-resolution-unreal-skins/downloads/unrealhd-v30-full.

Unpack the contents of the zip file to your Unreal Gold folder.

Run the game, and add "Unreal/UT: HD Skins Full" to the mutator window (when you launch new game you should see popup window with abilty to add the the mutator - after adding, it should be on the right side of this window, like on this below screenshot).




If you want to read more about this pack and see some screenshots there is a link to project site:
https://www.moddb.com/mods/high-resolution-unreal-skins.

Download Unreal DirectX11 Renderer for UT, UG, Rune and DX

Original location of files and info about renderer was here: https://www.moddb.com/mods/unreal-directx11-renderer-for-ut-ug-rune-and-dx but as I remember it was removed by creator due to demand of Epic.

You can still find it using Wayback Machine:

https://web.archive.org/web/20221009213308/https://www.moddb.com/mods/unreal-directx11-renderer-for-ut-ug-rune-and-dx/downloads/unreal-directx11-renderer-for-utugrune-hp12-st-cbu-and-dx

Unpack files.

Copy the following files from the Common folder: D3D11Drv.int , Effects11.dll and d3d11drv folder to your Unreal Gold 'System' folder.

Copy d3d11drv.dll file from Unreal Gold_227i to your Unreal Gold 'System' folder.

Open tessellation.cfg file from Unreal Gold_227i and add content from Comment section to this Mod (comment of darknovism from Oct 29 2020). I can't list it directly because one of those file names Steam shows as a bunch of hearts :(

Update!

Fellow Unreal fan rowan_u provided us with darknovism comment on imgur:

"Thanks very much, here is the text from that darknovism comment if anybody needs it.
https://imgur.com/a/AVzGkAo "

Save changes to tessellation.cfg.

Copy modified tessellation.cfg file from Unreal Gold_227i to your Unreal Gold 'System' folder.

If you are launching the game for the first time then select D3D11 Renderer. Alternatively go to preferences with tilde (~) button to open up the console and type preferences then change renderer to DirectX11.

Download Normal and height maps for Unreal Tournament 99 and Unreal Gold for Unreal DirectX 11 Renderer from
https://www.moddb.com/mods/normal-and-height-maps-for-unreal-gold-and-ut-99-for-unreal-directx-11-renderer/downloads/unreal-normal-height-maps-dx11-version-10.

Unpack files.

Copy contents of 'Textures' folder to your Unreal Gold 'Textures' folder.

Download HD4K DDS External Textures v3.5 for the Direct X 11 Renderer from:

https://sites.google.com/view/unrealhdtextures/download-hd-textures#h.qjk8s7x6g81i

Unpack files.

Copy contents of 'Textures' folders to your Unreal Gold 'Textures' folder.

That's it. Play game.

It looks freaking amazing!