MacBook – When the apple store replaces a battery in a 13in retina MacBook Pro, do they replace the top case and keyboard/trackpad assembly too

Rather than ask us, you might ask your local store since they are the ones that will make the call.

My guess is if you have a functional problem where you loved the Mac to death and used it so much the keys are worn, they would replace it under AppleCare or the standard Warranty. I wouldn't expect warranty service for normal wear and tear and this will likely be up to them to make the call whether your specific instance is one or the other.

Also - do go in if you are frustrated with your purchase. Go now and not later, since the sooner you show them wearing, the sooner they can document it and it's more likely they'll want to replace something that is wearing out prematurely. Think like tires, if yours wear out in under 5000 miles (or km) it's clearly something the warranty should cover. Several years of wear isn't a defect in the manufacturing and just plain old you wore it out.

Please, do not attempt this yourself! A top case replacement requires moving EVERY component from one top case to the other and in some cases this includes the trackpad. I am a certified technician and this is something that is best done by someone skilled and in an ESD-safe environment. Go to the Apple Store and let them replace it for their fee or find an AASP that might be cheaper.

Should you still want to try it yourself be warned, ESD damage is very likely plus there is no guarantee on the part you purchase. You really do have to be careful with this because trying the wrong one could mean the parts won't fit or the keyboard isn't compatible with the logic board connector. Having the work done by someone with direct access to the Apple part means that the work and part are guaranteed so should there be an issue with the replacement or the repair you are covered! Cheers