Yes, by now you realize this is not a short-term proposition. If you only look at the amount of time and effort involved you'll probably quit now. But, what happens to your folks? It'll not get better the longer you wait or ignore it. Take the one-step-at-a-time approach, you'll be surprised at how much you can accomplish.

Set up a regular visit to the folk’s home even if it's only once or twice a month. Have them pull together all the paperwork they can find but DO NOT let them pitch anything! (they're only trying to help but they could make it worse) Most older people are in the habit of not throwing things away which is good and bad. You need to separate the wheat from the chafe. Old checkbook registers are especially valuable tools since most older folks do not use debit cards. Credit card statements also.

Make plans to visit the safety deposit box to see what's been put away and forgotten.

Take a deep breath and start but do start!