From a friend who sweated blood from his eyeballs to get the stuff that was harder to find than hens teeth!!
Front wings are direct replacements on most kits, it is when you come to the rear doors and quarters that you start to have hassles, if you get the proper quarters and real doors then there is alot of cutting a fabrication to be done on the rear arch and quarter.
If it is stick and bond then it is not too hard...........but you will always know it is just stuck on!!!
If it is the L'aunsport kit from Japan then i would not bother, i saw their car up close when i was there last month and it was not the best quality.