I used Crowbar, MS3D, and Notepad++. As MilkShape 3D is not free software, a suitable alternative has to be found if you do not own a copy.
For this example, I'm porting the shotgun from Half-Life 2. First, I gathered all the model files.
I put them into a folder structured like this:
After that, I opened up Crowbar and set up the menu like this:
After decompiling, your files should look like this:
Then go into MS3D > File > Import > Half-Life SMD your Reference model. DO NOT rename your bones!
At this point however, were going to need the textures to make this work. Locate those and convert them to .bmp files with a indexed, 256-colour palette. Be sure that all image files have sizes that are a power of 2 and under 512x512! (Exception if your compilers support larger files, i.e. Xash).
It should look like this when you're done:
(But move them (the textures?) to your final folder! And be sure to select them in MS3D through your final folder!)
Back into MS3D and go to your Materials section. Select your textures and if you did it correctly, it should look like this:
After that, export as a Reference and move to your final folder. Move all your animations into your final folder as well.
I have no idea what I was talking about here originally, but to quote THePrince,
"...just compile the model [normally], then open MS3D, go to Tools - Karisto's HL MDL Decompiler, uncheck everything except Sequence SMDs (leave it checked) browse the model directory, and decompile... if you try to import the animations on MS3D now, they should work".
Also, what was I going on about here too initially? Half-Life 2 by default uses a viewmodel FOV (that Half-Life 1 lacks) and a different default_fov.
Here's the finished result:
Hope you enjoyed! Post here or PM me for any comments/concerns.
First tutorial here, don't kill me!