[Q] Root Explorer no R/W option on /system/app

Hi,

just installed GALACTUSMOD 4.2 XXLT5, i wanted to push/move stock FMRADIO.APK and EMAIL.APK. I already installed Root Explorer to be able to push .apk. but i have one problem. /system has RW option, /system/app no RW option. i tried the other way of pushing using terminal yet still cant locate it. does anyone can fix this? or does anyone can make a tutorial to enable the RW option for /system/app so i could able to move apk's I wanted to have on my phone.