1.show from www.thesims.com
2. and any kind of paint (even Plain Paint will work it come with your computer)
LINKS at bottem of page
And of Cores u need the sims
Step 1.
well first you download the sim show after that open the simshow files
Gamedata/textures
and get out a texture of your choise
Then dubble click on it and press Edit it will then open up in paint and you can change the out fit to a whole new style
STEP 2.
then after your are done with that go to file (in paint)and click on save as and look at the name of it it would look somthing like this B002fafitlgt_
see the under score (_) after the under score you put the name _shellyjames
but you can not erase the nubers or letters befor the under score or it will not show up in your game
and you have to change that name so it will not over write anoter skin
STEP 3.
then Press SAVE then it will save it in the texture folder in the sim show gamedata then scroll down and find in left clik copy then go into yor sims folder (programfiles/maxis/thesims/gamedata/skins) and start your game and cheack out that cool new skin YOU made good work
Simshow SEE SOME EXSAMPLES