Wrote up a quick tutorial:
1. You need a pic for each player (obviously

).
2. Download
PictureTray. This will allow you resize the saved pics into a 88x124 format and 33x46 format with a jpeg extension. Make sure you copy the resized pics cause they are deleted after you shut the program. Also make sure that the aspect ratio is turned off in advanced settings and that the output folder is on a separate directory.
Once done with this you need to find the photo ID number for each player (look at the rosters on NHLview) and put them in a XXXX.jpg (if less than 1000 or 100, the format must be in a 0xxx or a 00xx format).
The images must then be put in the NHL 2004\fe\nhl\images2\faces\med or small folders.
3. Download
GIMP. GIMP allows you to create the "transparent" backgrounds for the PNGs. These PNGs must be in a 128x128 format (see below, save the pic as a template), with the source image being 100x128 in order to be put into the center.

4. Code-writing. This is likely the most annoying thing around. Open up a document in notepad and save it in a bat format. The code should be written like this:
gfxpak -cp -real ugi\gamedata.viv\Aab_V_4210.fsh Lastname_Firstintial_ID.fsh Lastname_Firstintial_ID.png PORT
gfxpak -p ugi\gamedata.viv Lastname_Firstintial_ID.fsh
Once this is done, put it into the main NHL 2004 directory. Run the BAT file and you are done.