[Q] how to edit smali files into an android rom (telephony-common.jar) ?

i want to edit a smali file that it is into telephony-common.jar ! (telephony-common \ smali \ com \ android \ internal \ telephony \ MccTable.smali )
but smali language is very difficult to read and edit!
is there any way to convert smali to java?
anyone can suggest me a way to edit it?