I've heard bad things about removing it from DE machines, but never tried it myself.

I removed mylar on a DE Time Machine without any issues, other than it's a lot of work.

i had some dirty dried up mylar lifting along the edges, trimmed it back with a new #1 hobby knife blade & covered the edge with some new mylar pieces, closed my eyes & continue playing pinball once you start removing that stuff snowballs into a nightmare job

You have to be more careful on DE games that B/W games. The printed layer can easily come of. Have seen that happen to a TNMT. Would not recommend to use the freeze spray method and you may have to be careful with chemicals that help remove glue. Best method may be to use a hairdryer to melt the glue slightly and peel the mylar of bit by bit.

What is the best way to jam something under the mylar (esp up against an edge) so that you can cut those nasty edges away safely without cutting into the wood?

-mof

I've had success using a plastic putty knife and then cutting with an exacto knife.