Trezor Setting

[Kongxx]

Is it possible to reset the PIN and phrase of a Trezor if it was set before?

[shinratensei_]

If what you mean is wiping the trezor to reuse it then yes it can.
But if what you mean is retrieving the addresses because you forgot the pin, then the only way is by reinserting the same seed phrase into the device after wiping it.

Remember wiping the device reset everything including your seed phrase.
Look up their official site, I'm sure they have comprehensive guide about how to do with step by step screenshot.

[DeathAngel]

To reset your PIN & seed phrase on a Trezor:

Connect your Trezor to a computer.
Open Trezor Suite.
Go to Device Settings → Wipe Device.
Confirm on the device to erase all data.
Set up as a new wallet to create a new PIN and recovery phrase.

Only do this if no funds on Trezor as it will permanently delete the old wallet & funds unless you have the seed phrase.

[Charles-Tim]

There are also articles by Trezor that can help you easily understand how to wipe your Trezor device.

How to wipe your Model One
Factory reset: wiping the Trezor Model T in the Trezor Suite application
How to wipe your Trezor Safe 3 - Factory reset
How to wipe your Trezor Safe 5

[passwordnow]

Is it possible to reset the PIN and phrase of a Trezor if it was set before?

Yes, possible as given the details on how-to. May we know what's the context behind that or you just want to wipe out the trezor that you have? Don't make a mistake doing that or you'll regret as long as you're guided and as said, there should be no funds anymore at that HW when you do the wiping out. And more likely, this thread is specific on Hardware wallets.