That's a tough call. Normally (without a slippery metal roof) I would get to the lower roof(s) with a ladder and then a short ladder to the top or highest roof. Then with a 75'/100' extension hose on a good pressure washer use that to spray or blow out the gutters from the highest roof gutters. Wow tough call and risky job. A lift or crane, "cherry picker" rented or a friend that has one would be much safer. Running a "safety line" tied to something pretty permanent over and on the other side of the house (on the ground like your truck, with just enough slack or length to get you within a few feet of the edge of the roof and just close enough to get you in a standing position to the gutters and no more would be the safest IMO. Head to the outdoor store and get some good climbing rope to tie yourself off if you decide to get up on those roofs. Maybe they even have a safety belt or harness for doing that? Stay Safe.

MikeR

There's three of these in stock at my local Lowe's for around $54 bucks and probably around your area at the big box stores too.