This


http://www.uesp.net/wiki/Dragonborn:Old_Friends

Does not help me.

Though i have completed "Healing a House" and "Reluctant Steward", when i talk to Neloth, i can't start the quest, and he does not give me the ring.

I thought maybe i had to kill that lone ashspawn first, and then talk to him, but that didn't work either.

How do i complete this quest?

Try waiting a few days, it should fix it.