I had a ec 65 for several years.
It's pretty easy to do.
Take all the nuts off( mark it as someone else said)
I bought some filter cleaner at lowes, for cartridge filters and de filters.
Just carefull when you lift lid off
Their are lots of tubes that filter the de.
I would rinse the tubes with a steady stream( dont use a power washer or you will trash the tubes)
Wash , then put some of that cleaner or you can use tide detergent and soak the tubes for about 2-3 hours, drink a couple of beers while waiting, then re rinse

When you put the screws and nuts back in just snug them dow, then alternate tighten one, skip one, and so on sort of like lug nuts on a car, don't overtighten them .

Then when you re earth you will use 6 scoops instead of five. I usually had to take my apart once during pool season.

I recommend the de scopp that pool stores sell made by hayward, they are a few bucks and worth every penny. so you can acurately add the earth. I got really screwed up with a coffe can and had problems with too little or not enough earth

Have fun, it's not to bad
Mike