This method is from a Chinese player. To respect his effort, I add the original link as below.
http://www.diypda.com/viewthread.php?tid=478&a mp;extra=page%3D1
Before you make unlock your 6700, please make clear what is CID and superID. The CID is HTC customs for different carrier code. For example, The CID for Verizon is different with Sprint. You can not make the Verizon ROM works well in Sprint phone. The SuperID is just clean the CID limited, it means you could let any carrier's ROM works well on your 6700.
Please note the SuperID is useless for ESN.
I only translate the important words which is related the unlock method.
1) How to check if your 6700 has superID?
a) Install ActiveSync into your computer;
b) Cancel the USB connection in ActiveSync connection option page;
c) Run MTTY.exe and select the USB mode;
d) Type USB>task 32, if you get the feedback level=0, it means you have already gotten the superID. If not, you get the level=FF, it means your 6700 is locked to a appointed carrier.
2) How to get SuperID?
a) Download the attached file;
b) type ##3424+talk on your 6700 and press "start";
c) Run QPST, Start Clients---EFS Explorer, then press "ok";
d) Select folder NVM/NVM, put the attached file (decompress it first) into this folder, then quit QPST;
e) Press "stop" on 6700, then your phone will be restart, you get the SuperID already!
You can upload any 6700 ROM into your phone!
P.S.: I can not upload the NVM file, you could download it from the above link.