Considering you already followed the http://www.turokforums.com/t1-moddinguser-content/t1-modding-(get-started)/msg3301/#msg3301%5D Basic modding guide.
Here I wanted to give a briefing on editing and playing textures in Turok I was asked by a few people so here hehe. This is specific to how I do it myself. The steps are small but I wanted to spread and go into detail on some.
Step 1: Create a new folder on your desktop and name it “textures”
Step 3: Find the texture that you want to replace. You could need/use this original texture as a base for editing on specific textures such as weapons or other non flat textures. But what you really need is the file name. In this case I will use tex0129_00.png
Another way to view all the textures at once rather then fliiping through them to find the ones you need. Use Kaisers drop of textures https://dl.dropboxusercontent.com/u/18609/turok_texture_slideshow/Thumbnails.html
Okay this is the texture here we will edit. tex0129_00.png
Step 4: Get your own texture and rename it to the specific file name of the texture you want replaced.
Step 5: In step 1 you made a textures folder place your renamed png texture file in there.
Step 6: Right click your textures folder and add to archive or zip.
Step 7: Take that zipped folder and place it into your mods folder and rename it to textures.kpf. You can name your kpf however you wish as long as the textures folder is inside named correctly and your kpf is in the mods folder.
After you rename your done. The example below is not to match or anything its one of the first textures in the game that everyone should be familiar with so I used it as an example. I just through a texture I have that is 2048×2048 in here for a test. Thanks enjoy hope it helps.