Quoted from Mikala:
Explain why? So it is rusted. Let it sit in an shallow bath of evaporust, go over with 0000 steel wool, polish with mag polish. Done. Why remove? You could/will cause more damage removing.
One of the main reasons bottoms of backglasses flake so badly is the Windex effect. Windex is sprayed on the glass, and it runs down and gets inside the lift channel. It then gets wicked up on the back side by the inks and the process begins. Soaking the lift channel in anything is pretty much guaranteed to cause damage to the glass. You can't avoid it. To get the upper part of the channel into the Evaporust will cause the Evaporust to run down between the glass and the channel and you will damage it.
I've removed these in the past that were very rusted. There is no adhesive in the channel, only some tape, and then only pieces of it. To remove the channel, put the glass on carpet face up. Use a rubber mallet and a piece of a 2x4. Place the 2x against the channel, then gently tap. Move it around. It will come free. And you will not damage the glass if you are careful, meaning don't hammer on it and don't make contact with the glass with the mallet.
When these are really rusted, even if you get it off and soak it in Evaporust, it will never look as good as a new lift channel. Those things are a shiny plate and when they are rusted, that goes away and you'll still have pitting, even if you get all the rust off. I've never owned a Bally/Williams game that I did not replace this part. It's right in your face and it will make a decent glass look shabby.