If you're referring to my U-boats Aces Faces Mod, I can tell you how I did it. I just opened up one of the existing files with the multiple images, down-sized the image of the real aces' face that I was using for the main image file to a size that would fit just within the individual frames, and pasted the small images onto each frame of the strip.
IIRC, 4 or 5 of the pictures needed to be a little smaller than the one for the first frame or two, so that the colored frame (blue, tan and red I believe) would still show around the edge of the picture. Also, for the couple of pictures that needed to be red/shaded (I guess for when they're hurt or dead), I experimented around a bit and figured out a way to flood-fill the image with red (after setting the flood fill tool to be partially transparent), and then pasted in the red-filled image into the frame.
I left the Ace's picture up in one file, on which I did the resizing (and, at the end, the flood filling), then selected and copied his reduced picture, switched over to the second file where I had the strip/frames open, and used "paste as new selection" so I could position the pasted picture into the appropriate frame in the strip.
And on the main picture file, I just opened one of the existing ones of those up as well, and did the same thing in terms of reducing down a picture of the Ace's face until it fit so I could paste it down on top of the existing face in the original picture, leaving the black space in the bottom just like it was in the original game file's picture.
I used Paintshop Pro 7 as well, so I'm sure you'll get it if you keep trying - I don't know much about the program either so I just had to experiment with various sizes and things till I got it right.
Once you get the hang of it, it can be fun to put other people's pictures in as well - right now my Father is my watch officer on my Type IXB on patrol in July 1941 (looking sharp in his USN Lt's uniform from the war), on loan from the naval attache's office in Berlin as part of BdU's program to reduce tensions with the US and try to keep them out of the war - guess I'll have to transfer him off the boat if we survive until December 1941
Good luck!