Well if you tracked with it you shouldn't have to. Or do you just wanna hear old tracks REAMPD through it. Out from PT in to 710 out to PT . Lots of ways to do it but thats how its done.
Or set up a hardware insert in a plugging box . First slot is best for me so everything after has that sound. BUT re amping like guitars and such require a signal to be much lower at line level . BUT being a preamp it will accept a wider range of signal so if it has a input adjustment you should be good. If not send it out use the fader to adjust to necessary levels then bring it back in on a new tracks . You can then print it to disc or use it as a permanent hardware insert in your PT session.