BEHOLD, THE MAGIC SOLUTION.
Take some Dental Floss, a Qtip, and GOO GONE.
Position your dental floss behind the battery.
Pull to one side.
Wet the Qtip with Goo Gone generously, hard to get too much.
Wet the other side of the floss with Goo Gone.
Repeat this process for 30 minutes in this case. You’ll start to feel when that Goo Gone is getting in there nice and good. You sometimes need to use a little bit of force.
WARNING: Do not pour the Goo Gone while the Mac is upside down — remember your LCD Monitor is delicately sitting underneath this all! I saw some pour soul report they melted their screen and had to buy a new Mac. I stood mine up on the side and flossed it. Great technique.