Gnosis Chain is moving to Gnosis EEZ
These guides cover running a node and a validator on Gnosis Chain as it runs today, and stay valid until the fork. At activation the validator set retires and nodes keep only an execution client. See the move to Gnosis EEZ.
Managing an existing validator? Go to Validator withdrawals or Voluntary exit.
Run Validator: Nimbus
Refer to Run a Beaco Node + Validator: Nimbus