Well you need some tools, x360 usbpro v1 or v2 and/or a ck3i. Read the tutorial's for flashing a slim drive on here. It's going to cost you alot to repair this issue.
Just send it back to the person who did the install to fix it or another well known modder on here. Probably be alot cheaper than buying all the stuff you need to reflash your drive.
Sent your new rgh nand image in pm..
The drive may not be locked if its still not reading games after you reflashed your rgh image.