Breaking news: Apple just got out of the screwdriver business.This is only one of many interesting tidbits that iFixit, which helps do-it-yourselfers repair Apple products, uncovered after taking apart a new MacBook Pro Core i5 15-inch machine. "Aside from upgrading to Intel's new chipset, Apple made a few tweaks in the hardware design," says Kyle Wiens, CEO of iFixit, a website that provides free repair manuals and advice forums for Apple product.Last week, Apple released an updated line of MacBook Pros with faster processors, graphic chips and improved battery life. Intel's Core i5 and i7 power the new MacBook Pro 15-inch and 17-inch machines, respectively. The MacBook Pro Core i5 15-inch machine costs $1,800.Every day, more people become new MacBook owners. Mac laptop sales grew 28 percent this quarter from the same period last year, to just under 1.8 million units, Apple announced earlier this week. High-flying Apple posted record quarterly earnings for a non-holiday period.Kyle Wiens, CEO of iFixitBut Apple doesn't make repairs easy for do-it-yourselfers, and that's where iFixit comes in. For starters, Apple puts "do not remove" stickers on its products. Many Apple product owners worry that do-it-yourself repairs will void warranties.Not to worry, iFixit's Wiens says: "I've read Apple's warranty in detail. It says if you disassemble your computer and damage it in the process, you've voided the warranty. But they can't legally tell you that you can't take apart your own machine and do repairs correctly. This won't void your warranty. Obviously, though, you can't use third-party parts."Weins' seven-year-old website wants to help Apple product owners replace worn-out iPhone batteries, swap screens, or put in a new hard drive or optical drive. Apple technicians at iFixit have written some 2,000 free repair guides that have helped people fix over a million devices. iFixit has also sold more than 100,000 Apple parts and toolkits.It should be noted that iFixit is not an authorized Apple service dealer. "Apple would not want their authorized service dealers taking apart their products and showing the public how to repair them," Wiens says.Wiens and his 25-person team recently checked under the hood of a MacBook Pro Core i5 15-inch laptop. Here are three things they learned:1. Does Battery Size Matter?The battery looked nearly identical to the battery in last year's MacBook 15-inch model\u2014only 6 percent bigger\u2014yet Apple says the new MacBook battery boasts a 22 percent increase in power, or two hours more of battery life.How is it possible that a battery that's only six percent bigger yields 22 percent more juice? "This tells us that the i5 architecture is dramatically more power efficient than the previous architecture," Wiens says.Greater power efficiency (instead of relying on a bigger battery) has another benefit: The MacBook Pro Core i5 runs cooler. Heat generated by a computer correlates directly with its battery life. The longer the battery life, the cooler the machine.2. No Longer ScrewedThe battery is just three screws and a connector away from being replaced. At Apple, though, nothing is this simple. Apple had been using 5-pointed Torx screws on its MacBooks, not standard 6-pointed Torx screws. So head to the hardware store and get a 5-pointed Torx screwdriver, right?"We did a little bit of research and found out that this particular [five-pointed Torx] screw has been patented," Wiens says. "It is illegal to import screwdrivers that can open this screw into the U.S. unless you buy it through Apple's sales channels. Apple sells the screwdriver for $40."To be fair, Wiens figures Apple wasn't so much in the screwdriver business; rather, Apple wanted to prevent ordinary people from being able to remove the battery themselves. iFixit found a way to remove 5-pointed Torx screws using a 1.5 or 1.6 mm flathead screwdriver.With the MacBook Pro Core i5, Apple got out of the screwdriver selling business. Apple switched to Tri-Wing screws\u2014a common enough screw used in Nintendo products. "We've been including this screw bit in our $15 toolkits for quite a while," Wiens says.3. Adjusting the "Rabbit Ears"MacBook casings are made mostly out of aluminum, whereas most laptop vendors have plastic shells. The problem is that aluminum blocks radio-frequency transmissions. This means Apple has to find openings for its Wi-Fi and Bluetooth antennae.In previous MacBooks, Apple put the antennae behind a rubber section on the hinge. With the MacBook Pro Core i5, Apple moved the antennae to the frame of the 3.5-inch wide optical drive slot, which should lead to better reception. "It's a very well-thought-out decision," says Wiens, adding, "time will tell how well this works in the field."Apple also moved the Wi-Fi and Bluetooth mother board so that it no longer requires wireless connections to be integrated into the camera cable, says Wiens, greatly decreasing the size of the connector.Tom Kaneshige is a senior writer for CIO.com in Silicon Valley. Send him an email at firstname.lastname@example.org. Or follow him on Twitter @kaneshige. Follow everything from CIO.com on Twitter @CIOonline.