Uff man there's a lot of ways this can go.
Freeze spray, any canned air, works awesome with Diamond plate games, but sys 11 can be tricky.
The problem with freezing is it can take the mylar up pretty quick with very minimal damage, but then leave the glue behind to deal with. My borther did a High Speed and the glue was impossible to get off.

I'm sure other people will have their stories

With either approach you run the very real risk of losing paint, insert text or both. So if you are not comfortable with repairing the damage, I would leave it alone and see if you can cut out the bubbled areas with an exacto knife. Then you could buff out the remaining mylar and even add a playfield protector for more shine.

The system 11's I have done in the past, I did with heat. For example the Space Station lost much of its insert text, but was repairable with the insert decal set. The mylar glue that was left eventually came up with alcohol and a plastic razorblade.

It definitely can be done, but just be ready to deal with the fallout that will most likely occur.

I get the Office Depot freeze spray. Do it in short bursts, small sections at a time. Alcohol and flour after to remove glue.
Good luck.