My parents funerals were also prepaid, the cremation and placement in the columbarium, and even the writing for on it.
They had previously told me that as the church person in the family, i was to plan the service and had listened to them regarding services they liked and hymns that they liked. Dad really loved a piper, so he had one. It was important to him, and you know, because of that, when it happened, people were touched.
Getting rid of stuff was also pretty well laid out, though things had changed as Mom died (got rid of a lot of cooking/baking/pretty things), then he moved into smaller & smaller locations and had disposed of most of his material goods prior to deaths.
It was relatively speaking, easy to know the asks for him.
So, have I done it. Dang, no. I likely should