After you finished decompile or extract open Xplore
open storage E/jarBOOM folder In jarBOOM folder you can see two sub folder "jar" and "unjar" open folder "unjar" here you can see extracted mig jar file.
Open folder "META-INF" in extracted mig. And go to file "MENIFEST.MF". But dont open it directly. press "8" on your phone keypad to edit file "MENIFEST.MF
As you can see in screenshot, you can rename "migv42" in two places.
And now open jarBOOM to pack or compile the edited mig
Open menu and select complie
Open "META-IN" folder
Select MENIFEST.MF
Write a name for edited mig After you finish compiling.. open Xplore an open jarBOOM / jar folder....your edited mig will be in jar folder