- Instruct the debugger to break-in, and memorize the two bytes at EIP.
- Replace the two bytes at EIP with EB FE that is JMP EIP.
- Detach the debugger leaving the application in an endless loop.
- Attach the other debugger to the running process.
- Locate the thread of the endless loop by switching between threads, and when found, restore the two bytes you memorized.
- Carry-on with the debugging using the other debugger.
Note, the patched thread could interfere with watchdog thread if any, however I haven't experienced it yet.