1. flash firmware 3.12 the exact same way you flashed firmware for ARHD 6.3. firmware can be found here in the 2nd post
2. when screen turns black or tells you to reboot, take battery out, IT'S REALLY IMPORTANT THAT YOU TAKE BATTERY OUT BEFORE IT REBOOTS
3. take out sdcard and remove PG58IMG.zip by powering down phone, removing sdcard, booting into hboot, then select recovery. IMMEDIATLEY put sdcard back in, and let recovery boot up.
4. connect phone to computer via usb, select toggle usb, select view folder when device pops up on computer (assuming you have windows), find and delete file PG58IMG.zip, then tap disconnect.
5. reboot into bootloader and it should say **LOCKED** instead of **REVOLUTIONARY** but don't you freaking worry about that because your phone will still work perfectly.
6. boot into recovery and swipe cache+dalvik or if you have it on you sdcard, flash "Android_Revolution_HD_Super_Wipe_Sensation.zi p"
7. now flash ARHD 4.1.13 or if your restore point was a ROM that supported firmware 3.12 then flash that but I got out of my boot loop by flashing ARHD 4.1.13. you can find it here
8. after flashing is done, navigate back to recovery's first menu and select reboot. your phone will boot up perfectly and now you can finish that sexting session you were having with the town bimbo.
X. if you somehow managed to not put in the sdcard fast enough in step 3 because of whatever freaking reason, don't panic, just put sdcard in, wipe cache+dalvik and reboot recovery.
this got me out of that very scary boot loop and i'm pretty sure it'll work for you to given you did EXACTLY as i said.
now you can retry flashing ARHD 6.3 again GOOD LUCK