iCloud keychain problems - asking passwords, can't change password, can't unsync Main symptom: When I reboot I get multiple prompts asking for the "local items" keychain password. 
Details: 


The password required is my old iCloud password, not my current user account password nor my current iCloud password
The keychain access program lists "local items" as a keychain until I log in to one with my old password -- after which it changes to "iCloud"
The option to reset the password for both local items (before entering the PW) and iCloud keychain (after) are both greyed out. 
I cannot stop syncing my iCloud keychain. When I uncheck the box, the box rechecks itself in a second or two.
to confuse things, I used my iCloud account as my login for the computer briefly


I have looked at several topics to guide me, but none of them have led to a resolution as it seems the problem is always slightly different. 

Any help is highly appreciated!
Sorry to bump an old thread, but I found this simple solution. At least in my experience, the password for the default keychain cannot be changed, so:

1) Create a new keychain (File→New Keychain… ⌥⌘N). I named it temp and gave it a simple password.

2) Right-click the temp keychain and select Make Keychain “temp” Default.

3) Select the original keychain.

4) Edit→Change Password for Keychain [name]… should now be accessible. Select it and change the password to your heart’s content.

5) Right-click the original keychain and select Make Keychain [name] Default.

6) Right-click the temp keychain and select Delete Keychain “temp”