Need to recap my Classe Audio DR-8 Amps - need suggestions

1: If you have any dc offset coming from the amp, you may hear it at switch on by a good hefty thump through the speakers.

2: And if it has a constant large amount of dc offset you can as gergeab said measure it with a DMM if you have one and know how to use it.
Or after the thump look at the bass driver will be in or out a little more than where it normally sits in it's rest state with no amp on, if there is dc present.

Cheers George

Caps that need reformed are garbage and should be replaced. If you've got DC on the outputs and you're cooking woofers there's a good chance that's the result of a cap leaking. My vote is recap before you're stuck replacing more woofers or transistors. They might have another 5 or 10 years left in them at best. Electrolytics aren't meant to last forever. 

Caps that need reformed are garbage and should be replaced.

This is not correct, I’ve done it many times with new old stock Siemens that have been on the shelf for 15 years or so, and other good quality ones, and I’m sure the ones in the Classe aren’t rubbish probably Nichicons.
So long as it’s done as I stated above it works great, that (10v-20v) is the volts you increase every hour or so.

That sounds very foolish and it's a great way to fry diodes, rectifiers, and transistors. The only way to fully reform a capacitor is to remove it, put it on a high voltage leakage tester, and watch the leakage drop off as you progressively ramp up the voltage to it's rating. That's impossible to do in circuit. Doing what you suggest would, at best, reform them to their idle voltages and no more. Even if it were a good idea, which it isn't, you'll never reform them to their ratings and you'll only end up with a unit that's just barely on the edge of leaking. Since the only way to do the job "right" (if there is such a thing) is to remove them, you might as well replace them.