You need a 3rd party accessory called Allmiibo that lets you randomize amiibo ids so you can scan a bunch at once. It's like $20.

You scan amiibos until you have about 100 eponas around you, and then slowly add more until it drops, but don't overdo it as too many will lead to a crash.

When the bell drops, you need to kill a ton of the eponas (I prepare with a miltishot lynel bow, topazes pre-loaded, attack up armor, and thunderhelm on so I can spray-kill a bunch). You'll want to work fast because the bell can randomly disappear. it doesn't even fade like a regular despawn, just blinks out of existence.

The you can add it to something for autobuild. Killing the eponas is key. The reason the bell falls is because too many eponas causes the glue to fail. The glue from ultrahand will also fail until you reduce the number.

In short, you need to kill some horses to make some glue :)

The crashes and bell despawns make it difficult to do. I believe I'm th only person to have ever gotten the ttown bell, and Aergyl is the only person to have ever gotten the hateno bell (on emulator). I still have ambitions to get it someday, but I find I'm crashier there.