To open a pinball machine up use the key to open the coin door or drill the lock if you lost the key. Reach to the top rail of the coin door and find a bar pull down on the bar they are usually old rusty and stuck. pulling the bar down will allow you to pull the stainless steel or chromed steel lockdown bar that covers the glass on top, pull it directly up. You can now Slide the glass out of its track towards you carefully though don't let it break in the middle. now you have access to all the plastic and rubber bumpers and can lift the Playfield up to access the components on the inside.