The JTAG signals are on the surface of the PCB at the test points. you will need to solder some leads onto the test points out to a standard JTAG connector then you can connect your JTAG tool (FlySwatter or similar).
The next part of the problem is getting into the chip. We did a little bit of work on making OpenOCD work with the Qualcomm Chips, however the people that did the work are no-longer with Qualcomm, so we ‘released’ the changes to OpenOCD. The changes are here: https://github.com/mentalbee/openocd64ref If you would like to pick up this work and extend on it feel free to take the code and use it as you wish. I have no idea if any of this works, or if you will be able to make it work…
Full Disclosure: I am an employee of Qualcomm Canada, any opinions I may have expressed in this or any other post may not represent the opinions of my employer.