I thought the two examples above were well stated, but perhaps you just wanted a little more information to further illustrate the frustrations of Americans with Hoover’s policies.
The first example that comes to mind was how badly Hoover was defeated when he ran for re-election in 1932. Although Hoover didn’t really want to run, he didn’t trust any other members of his party to stay away from radical solutions, so he made a half-hearted attempt at defeating Democratic opponent Franklin D. Roosevelt. He was crushed, earning less than 40% of the popular vote, a 28% decrease from his 1928 victory. He only carried six states in the Electoral College. Not only did the American people kick him out of office, they routed the Republicans from congress as well, handing the Democrats control of the House, Senate and the presidency.
During his presidency, there were many demonstrations and protests aimed at Hoover and his seeming inability to do anything to turn the economy around. Hoover was perceived at a “do-nothing” executive mostly because his policies either fell flat or he refused to take more direct action. He prescribed to the Coolidge view of a hands-off executive in dealing with the economy, but this doesn’t work during a depression. Direct action is needed, and Hoover simply didn’t agree with the economists who begged him to move.
Some of his policies that failed and drew immense criticism were;
Harley-Smoot Act: Despite warning from many economists, Hoover signed the largest protective tariff in American history. Other nations soon retaliated with their own, and American exports fell significantly.
The RFC: The Reconstruction Finance Corp helped protect banks and industry at a time when Hoover refused to give emergency funds to the hungry Americans. This was seen by the majority of Americans as classist.
The Bank Crisis: As Hoover left office, bank holidays were declared to prevent closings and runs.
Of course, the most obvious way in which the American people showed their disapproval of Herbert Hoover was by voting him out of office by a huge margin. Hoover got just under 40% of the popular vote and only won 6 states. This clearly showed disapproval of him.
A second thing that people did to show their disapproval was to name things after him. They used "Hoover" as a prefix to indicate that it was his fault (in their opinion) that they had to use those things or be in those places. The most famous example of this is the term "Hooverville" which was used for shanty towns erected by homeless people. I have also heard terms like "Hoover blankets" for newspapers that homeless people would put over themselves to try to keep warm while sleeping outside.