How does one get parent's to downsize items in their home?

The past few years I would ask Mom if she would like to donate items to a local yearly rummage sale that benefits the hospital, etc. and she would hand over one item. Guess one could say she is downsizing, one knick knack at a time.

Dad has a ton of notebooks with a lot of newspaper articles, wouldn't be surprised if he still has his first paycheck stub. And a workshop filled with things that he can no longer can use safely with his now poor eyesight, etc. Last year he finally got rid of an 1955 electric free standing saw that he was sure someone would want.... took many years to convince Dad that carpenters now use saws that have laser guides, etc.

I've been hinting about a really nice retirement village that has super large condos but not large enough to accommodate everything they have in their large home. Their home is very neat, not hoarders. But I dread the time when I would have to go in and sort through everything. But Dad says they are too busy to sort through all the paperwork.... too busy??? Maybe at their age, just getting dress is busy work :)

After seeing how slow they are in downsizing, it made me start to downsize myself.... to try to live simpler without all this stuff.