what methods did Otto Von Bismarck adopt to unify and integrate Germany?

Answer 1

He provoked a war with France, the Franco-Prussian war of 1870-1871. Germany already had a customs union and popular sentiment for a united country was strong. The 25 German states agreed to accept the Hohenzollern King William II as emperor.
Bismarck in general was a savvy politician. He granted extensive benefits to industrial workers (such as old age pensions) to defuse Socialism. One of his mistakes was to engage in a Kulturkampf, a culture war against Catholics (a big minority in south Germany and a substantial minority elsewhere). This included all kinds of penalties, restrictions on university placement for Catholic professors, etc. After about 10 years he realized the culture war was a mistake and dropped it.

Answer 2

Wilhelm II did not become Kaiser until 1888, and soon after he dismissed Bismarck. Bismarck used what he called "Realpolitik" to achieve his goals, and that did include wars with Austria and then France which were quick, successful, and surprisingly financially advantageous. (A problem for the future since this confidence would lead to World War One which in turn caused WWII.) Bismarck spoke of "Iron and Blood" - the use of force to achieve desired ends, but Bismarck was far more discriminating, calculatingly diplomatic and cagey than Kaiser Wilhelm would be.

Answer 3

Using nationalism to unify German states in a cause ( the Franco German War)

Using diplomacy to convince German states to partake in Prussian leadership instead of Austrian.

Making the French and British wary of each other to exploit their weakness

Answer 4

By making Prussia the dominant state in Germany and weakening her rival, Austria.