two questions please

1. Wife went to estate sale.Bought a California king four poster bed. We have a regular king mattress so frame is about six inches too long. I would like to know what the slot is for where the metal inserted in both side and footboard join together.

2. Redoing the posts. She does not think the wood is the color she really likes but the posts and headboard are a bit intricate. How can I get these posts sanded? Without spending the rest of my life trying to get into all the nooks and crannies? She is not fond of the painted look. It's my turn as she redid the new kitchen cabinets PERFECTLY!

Appreciate your knowledge