Use a butter knife to pop open the lid. Place the jar on the counter and try easing ... try a combination of both the hot water and butter knife tricks to improve your chances of success.

An curved arrow pointing right. When a jar is vacuum-sealed, the different air pressures make it hard to open. But you can use a few simple tricks to break that stubborn seal. Follow Tech Insider ...

Since a JAR file uses a standard compression algorithm, opening a JAR file is as simple as changing its extension from .jar to .zip and extracting the contents using a standard decompression tool.