First off you need vivmagic and ea graphics editor(eage).
1. using vivmagic unpack the file xplrcmn.viv
2. now open eage and look for the same file xplrcmn.viv
3. double click shoes.fsh and the names of all the shoes will be shown in the drop down tree.(example sh4b and sh4c are kobes home/away shoes)
4. find the shoe you want to replace,then the picture will show on the clipboard.
5.select import wizard and the option :import external file into current open image.
6. check to make sure the original bmp was replaced, then run viv magic to repack the xplrcmn.idx
7.done
sorry cant really go too in depth, i have to leave for work now. but experienced users of eage and vivmagic should understand