If your glass breaks:
If the glass breaks you can purchase a cheap frame from a store that is the same size (5x7, 8x10) and slide the new glass in.
If your picture seems to be sliding out of the frame: Remove picture, glass, and black back. Then press metal tabs "squishing them", making them more narrow.
Using drywall anchor: Remove screw from anchor. Using a Philips head screw the anchor into wall until flush (flat) against the wall. Insert screw into anchor and hang frame.
If the clock does not seem to keep accurate time and you know the battery is good, the hands are probably out of sync.
To Sync Hands: Remove battery, manually place hands in the NOON position. Reinsert battery and set time using the dial on the back.