After modding resources.arsc, you must re-sign the APK, or Android will reject it (signature mismatch).
While you can technically write a custom parser, several robust tools exist. Here are the most powerful ones: arsc decompiler
Android 10+ uses overlays to theme apps. Some ARSC decompilers now support splitting overlay packages and merging them with base resources. After modding resources
No ARSC decompiler is perfect. Here are common pitfalls: While you can technically write a custom parser,