FMC Stadium Superpack for FM13 trouble

Hi

I play FM13 using "FMC Stadium Superpack for FM13" & "FMC for FM"-skin so I have all these nice pictures of the stadiums in full game mode.
Currently I'm playing Tollnes (5000204) in Norway. This club isn't playable at the beginning of the game, I started coaching them in in-game 2014, so they were promoters from a lower non-playable league. Two seasons later I reached the Tippeligaen (highest Norwegian league) and I got a new stadium (finished). Now, I would like to add a picture of a stadium to the superpack. I chose one (attachment), set it in the right format (.PNG) & size (400x240), looked up the stadium ID (750708) and hoped renaming the .png in 750708, just putting it in the right folder, deleting cache & reloading skin would work... but it didn't.
What seems to be the problem? Does the stadium ID change when you get a new stadium (both my new & old stadium carry the same name "Tolness Stadion" ) ? I don't think that's it cause I tried it with the old stadium also. Is the fact that it isn't a playable team at the beginning the problem? Do I need to make changes to the 'config' XML?
Help me out please.

From what I understand you haven't added the image to the config.xml. Open the config.xml and you what you will see is basically a list linking each *.png to the stadium ID number in game. Copy one of the lines and paste it as the last in the list. Simply change the the details to those of the new stadium and image you are using. Should work.

Thanks