If you are talking about protected system files, you need to use Total Commander or Resco Explorer or ROMExtractor in order to extract and modify them.
Dude, so many times so many members here in this forum sayd that its not possible to put new roms without HSPL, we need to wait till its done, so dont try it if you dont want to KILL your phone, do you understand the words comming out of my mouth?
If you would have done some search, the minimal possible imagined search or reading, you would heve known that you need to use a custom SPL to do that.
So you need to wait for the HARDSpl or pay for the PSAS aka QMAT to use the goldcard function.