Oh, sorry! Basically, you need root explorer from the market. I know it costs something like 3 bucks, but in my opinion, it's totally worth it if you do any mods on the phone at all. Messing with framework-res.apk with other file explorers can spell disaster. Root explorer is the only one I really trust.
1.) Using root explorer, COPY your framework-res.apk file at /system/framework/framework-res.apk to somewhere on your sd card for safekeeping, just as a backup.
2.) Move framework-res.apk from this thread's "stock icons - percent battery.zip" onto your sd card, and move it into /system folder on your phone.
3.) Long-press on this framework-res.apk in root explorer, and select permissions. Change permissions to: Owner: read/write, group: read, others: read.
4.) Move this framework-res.apk, now with the proper permissions, into /system/framework folder, and let it overwrite the original framework-res.apk.
5.) Restart your phone!