It's pretty easy. Take off the pump head and turn it over. You'll see a long center bar which needs to rotate to disengage it from the pump housing. This bar is the central support for the ceramic impeller shaft.
Once the bar is off, you'll be able to remove the lollipop shaped round cover. This fits into the housing precicely so you'll need to look carefully to see the separation. At this point you can simply grab the impeller and carefully lift it straight out.
You can then pull on the ceramic shaft and pull it straight out too. They're not terribly easy to break but it is possible. make sure it doesn't roll off onto the floor.
Once everything is open I usually use a small toothbrush to clean out the impeller chamber and impeller.
Once you're ready to put it back together, just push the ceramic shaft back into the small rubber grommet. Everything else goes back into place in reverse order.
Good luck. Sometimes after you service an Eheim, it makes a bit more noise than average for a few days.
Once the bar is off, you'll be able to remove the lollipop shaped round cover. This fits into the housing precicely so you'll need to look carefully to see the separation. At this point you can simply grab the impeller and carefully lift it straight out.
You can then pull on the ceramic shaft and pull it straight out too. They're not terribly easy to break but it is possible. make sure it doesn't roll off onto the floor.
Once everything is open I usually use a small toothbrush to clean out the impeller chamber and impeller.
Once you're ready to put it back together, just push the ceramic shaft back into the small rubber grommet. Everything else goes back into place in reverse order.
Good luck. Sometimes after you service an Eheim, it makes a bit more noise than average for a few days.