When you say you have a brick, are you getting error error 160-0103 on bootup now?
Options:
1. Did you have CBHC installed? if yes, you may still be able to boot into FTP to fix the files.
2. Do you have a Full Nand backup you took before the changes were made? Specifically mlc.bin ? If yes, as the other folks have mentioned you may need to do an mlc restore. Please note that the the link provided in the last post is primarily for restoring SLC.bin.. A much better guide specifically for only mlc.bin would be this guide here =>
link .. Restoring just MLC is actually not too bad as it does not require a teensy , and only requires 5 solder points and 1 trace cut. ... (I've performed both MLC and SLC hardmods and the MLC mod is 10x times easier than the SLC mod.) .... again only useful if you have a Full Nand backup before the mod was made.