Can't edit System files in El Capitan

[trumptor]

I'm having trouble editing my system files in El Capitan. Specifically platformsupport.plist. I went to the root of my drive an added myself with read/write privileges but i get this error all the way back the the root system file.



i can't imagine why i shouldn't be able to edit these files.

 

[RehabMan]

I'm having trouble editing my system files in El Capitan. Specifically platformsupport.plist. I went to the root of my drive an added myself with read/write privileges but i get this error all the way back the the root system file.

View attachment 155213

i can't imagine why i shouldn't be able to edit these files.

http://www.tonymacx86.com/el-capita...-changes-workarounds-current-information.html

 

[trumptor]

I did that but i still can't edit the actual installer. Like the ones that are on the usb.