Can the one who endows change the custodian of the endowment? The Grand Ayatollah Sistani’s answer

The Grand Ayatollah Sistani answered a question about changing the custodian of the endowment (Waqf).

Question: Can the one who endows (Waqif) change the custodian of the endowment?

The Grand Ayatollah Sistani: Cannot do so unless appointing the custodian has been mentioned as the responsibility of the one who endows at the time of writing the deed of endowment.