That is a 2.5" SATA hard drive. You can use a SATA-to-USB adapter, like this one, or a drive enclosure, like this one. Just search for SATA-to-USB adapter or enclosure, as there are hundreds of them. I have a NexStar adapter, similar to the first link I gave you, that has worked well for me for years. I've also used Sabrent products, such as the second link, which also worked well. It's not a complicated purchase, they are fairly generic in their function, though the form factor may differ. Probably any decent brand name connecting a 2.5" SATA drive to USB will work for you. Whenever touching components or working inside a computer, wear a grounded wrist strap, also called anti-static wrist strap, ESD wrist strap, or ground bracelet. It's a cheap and sensible precaution. Rest the laptop on an anti-static mat or at least a reasonable alternative such as corrugated cardboard.  
Hello,   A recent Kubuntu firmware update bricked my trusty old Inspiron 3521 that I purchased almost 10 years ago. I haven't opened the chassis yet, but would like to get advice on an external HDD enclosure so that I will be able to transfer the data over to a new laptop. All I know about the hard drive is what is on my invoice. It says the following: Hard Drive 500GB 5400 RPM Hard Drive [342-5185] Can anyone recommend an enclosure with only this level of detail, or must I remove the drive first? Thanks!
HDD Enclosure for Inspiron 3521?