I have installed front swaybars on many GP's, and never once had to lower the subframe.
There are writeups in the "Suspension" section on how to install a swaybar. Raise the entire front end, support on jack stands, and turn the wheels to gain access for the swaybar end links to hook up on the control arm. With time and patience, it can be installed.
As for the Auto Zone employee saying that the subframe bolts need replaced, I have removed them before for transmission side cover removal and I reused those bolts. Never had any trouble with them coming loose.
