It's very simple. Email an appropriate set of MPs regularly about your concerns, get out and protest in the streets, tell your friends, family and coworkers about the problems you see, join any political party of your preference including the left-wing parties, start online groups, etc About reducing immigration substantially, which is in economic terms called the reducing the labor supply, so employment opportunities go to Canadians and not foreigners. That is what helps grow consumer spending and a huge cohort of other economic benefits for the Canadian economy. We also must decrease immigration from non western-aligned developing countries,  many people from developing economies have grown in an environment where being selfish and abusive is a normal way of living, stepping on others to get ahead, so they bring that unhealthy attitude to Canada, and wrecks society. So there are all sorts of economic and social benefits to reducing immigration! Let's get on it!