Template.png
[Hide] (195KB, 2048x2048) lego.png
[Hide] (597.8KB, 1750x1868) >>1789
"For you" - Dark Vader
If you only want to change the skin ('texture') of the model, rather than the actual 3D shape ('mesh') then yes. The rest of this post is just explaining behind the scenes, for fun.
Did you make any of the kits? If so you may recognize the first two pics. The first is a simple template someone made, showing how each part of the texture image map onto the different areas of the clothing. The second is more detailed. As the original filename suggests, it shows the actual UV mapping; which pixels in the image are mapped to which position on the faces of the 3D model. That's how most games paint a whole 3D model using simple flat image/s.
The third pic is a bit more complex, mainly because I was rushing to get some of the models done before the cup started and as a result did a shortcut hackjob.
Start in the top left corner. That's the 3D model I was given, then we auto-transfer and/or paint 'weights' from the normal PES player onto the 3D model to let the game know how to animate the model (the hip weight and right thigh weight are shown). We've done this, so you don't need to care about it unless you try to add/change 3D props.
The next images (2) show the 3D mesh and how it maps onto the image. The UV map I made is broken into pieces and overlapping because it was rushed, but I spent a couple of minutes and got it to be a more intuitive mapping in (3), where the head becomes a front and a back half you can easily paint. So when you have a decently made UV mapping like that, changing the face, shirt color, etc. is as easy as inserting a properly-made image.
Small note: we convert the PNGs to DDS files, which is extremely easy to convert ([Open]->[Export as...] lol), similar formats but DDSs can store mipmaps (which /eris/ abused to make their kits change color, see https://erischan.org/b/res/2157.html#2793 )