This Agreement shall not be modified or amended except by a written instrument, signed by the parties hereto.

除非双方当事人共同签署书面文件，否则本“协议”不得修改或修订。

youdao

This Contract shall not be changed verbally, but only by a written instrument signed by the Parties.

本合同以口头修改，而须经双方签署书面文件后方可修改。

youdao

The king signed the instrument of abdication.

国王签署了逊位的文告。

youdao

In a statement, Mr Bowen said he had "signed the legislative instrument designating the Republic of Nauru as a regional processing country".

BBC: Australia to send asylum seekers to Nauru this week