Can I just take out the old glass sliding doors and replace them with new ones without ripping out the frame?
Sure, if they're available. Most sliding doors simply lift out. Some have a retention mechanism that would need to be removed first.
You'll probably need to level the doors to fit the frame using built-in adjusters, and verify that the latch hardware still aligns.
Probably not. Each manufacturer makes their equipment differently (frame dimensions, track style, roller mechanism, weatherstrip design, etc.) Even if you were lucky enough to identify the brand, chances are that the designs have changed along with modern focus on efficiency.
Slim to none, I say; and I have repaired more than a few. Just internet search "sliding glass door rollers" and you will see just how many different designs are out there.