You can't "transform" a single image file from one style to the other. The 2D style kits and the 3D style kits are separate images. You can replace them though, by replacing the images in your existing Kits folders; as long as the file name on the new image file matches its older counterpart, the config file will recognise the new image once you reload your skin in the game's Preferences menu.
That's also how we update kits when we get new or personalised designs.
Ok, the problem is that I made 2d kits, but doesn't show in match, it shows the old kits, not the one that I made. That's why I wanted to make them 3d, so I can see them in match too.
I don't know how to create new ones - it seems to require some ability with Photoshop or a similar graphics program. But if you're able to get someone to create a new one for you, the process of updating the image in-game is the same as I described earlier. The 3D match kits are just contained in a separate folder with its own config file:
The FM Editor allows you to create alternative kits using a limited range of options, but I believe they can only be applied to a game from the very beginning of the save.
Yeah rocheyb I knew they are 2 different things, but I thought you can somehow "transform" the 2d in 3d. Anywho, thanks for help, I'll ask someone if they can make 3d kits for my side Venezia.