How To Open The SIM Card Slot On Your Android Phone Without The Ejector Tool
So you're in a pinch, and you need to swap out the SIM card or install a microSD in your Android device, but you can't find the nifty little ejector tool that came in the device's retail box. Fret not, however. You can eject the SIM tray with any number of things lying around the house. (If you've got a newer phone, you might be able to avoid this whole situation thanks to eSIMs.)
You'll need to locate the tray if you've never accessed it. If you have a case on your device, remove that. Now, check the edges of your device for a small oval-shaped or rectangular cutout. You'll see a pinhole inside the cutout. Make sure the hole is inside the cutout because there might be other holes like microphones nearby.
SIM ejector tools are typically small pieces of metal with a flat-ended pin sticking out. If you had one, the pinhole on the cutout is where you'd insert it, but since you probably can't find it, we'll have to seek out other means. This is an excellent time to note that you should avoid poking your device with sharp, pointed implements like safety pins, thumbtacks, sewing needles, or toothpicks, which can puncture the battery, destroy waterproofing seals, or short sensitive electronics. There is a safer way that doesn't involve sharp objects.
How to eject the SIM card tray without the removal tool
Any object or implement with a flat end that fits into the SIM ejector hole will do the job effectively, but a small enough paperclip is by far the safest and most recommended. First, turn off your Android device (while it is possible to eject the tray while the device is on, it's not recommended). Bend your paper clip straight, insert it in the SIM tray pinhole, and press until the tray pops out (via Google). Try to push slowly and gently.
If you don't have a paperclip, there are other options. Straightening a staple with flat ends works, as does cutting off the sharp point on a toothpick. Most earrings also have flat tips, so these also work great. Mechanical pencils can work, but be careful not to snap the lead off inside the pinhole.
Now that the tray is ejected, take a look at it. Most devices just have a single SIM card slot, but some might also have a spot for a MicroSD card and/or another SIM card. Add, remove, or swap any cards as needed. The cards will lay flat and fit snugly into the slots. Once that's done, slide the tray back into place. It only goes in one way, so no worries about installing it upside-down. Turn your device back on and you're all done.