don't waste your time with it. get a digital one to replace it. most of us throw the one you have away and get a Hunter or Honeywell digital one.
do a search on the subject. lots of posts and threads on thermostat replacement with pics.
i deleted your other post. you can't post duplicate threads.
if you'd like, i can move this to the appropriate section, General Tech and Repair.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC