MacBook Pro Trackpad popped
If you are still happy with the performance of your macbook pro, I would recommend replacing the battery and the trackpad (in case it was bent when it popped). The replacement parts are fairly cheap and easy to install.

Ifixit has repair guides and parts available and are quite a reputable supplier of non-oem replacement parts: (the links are for the 13" model)

battery replacement: https://www.ifixit.com/Guide/MacBook+Pro+13-Inch+Unibody+Early+2011+Battery+Replacement/5116

trackpad replacement: https://www.ifixit.com/Store/Mac/MacBook-Pro-13-Inch-Unibody-Mid-2009--Mid-2012-Trackpad/IF163-025-1

p.s. I have no affiliation with ifixt or the links provided above, I simply have happily used their services to fix an aging macbook pro (2010) in the past.