Complex sentence: When Brice took charge in 1864, regulations were finally up brought up to date, and to officially include examination of candidates for the paymaster department, which included writing a business letter, solving mathematical problems, and testing on accounting and pay systems.
Split into simpler sentences: When Brice took charge in 1864, the regulations were finally brought up to date, and officially included the examination of candidates. This took the form of writing a business letter, solving mathematical problems, and knowledge of accounting and pay systems.