The phrase "in full" means as many as are necessary to complete the task. They were to use the gold and silver to buy all they needed in order to worship God in the the temple. AT: "Buy as many of the oxen, rams, lambs, grain and drink offerings as are needed" (See: [[rc://en/ta/man/translate/figs-explicit]])
The phrase "your brothers" refers to the people who were doing this work with Ezra. AT: "your co-workers" or "your companions" (See: [[rc://en/ta/man/translate/figs-metaphor]])