I opened the back cover, under which the heating sits (20 short screws), then i have direct access to the bearing, which is held with 4 screws. When i remove them, the drum sits a little lower (perfect for swapping the belt, which is behind the next layer of sheet), i can pull out the bearing after removing the E-ring and washer on the axle. It was a plastic bearing (Teflon or Nylon?), pretty yellowish and totally dry, with some brown stain on it. I cleaned it and it was rough inside, so i guess some dust/debris has worked itself into there. The axle is polished steel, so the lubrication (silicone grease) should do for quite a while, because the rough surface always keeps a little of lubricant in there. I will look up the part to order it ahead of the next time the thing starts to squeak.

I really was expecting a sealed ball bearing, but the manufacturer seems to include a little bit of planned obsolescence regarding the mechanics.

Putting it back together just requires to lift the drum using a piece of board in the right length (a few mm longer than the distance to the floor, there's room for tilting) until the screw holes of the bearing housing are aligned to the thread holes. Easy and doesn't need much space.