Those must be dealt with too, but will be more more difficult. Until repatriation and expulsion are being openly discussed very little progress is being made. Demographics are destiny, and unless you undo the demographics you can't undo the destiny.
"Multiculturalism" is a big tent. In fact despite being the leading conservative site on the net, for many years articles strongly opposing immigration could not be posted here at Free Republic. It's only in the last couple of year that the heckling leftist accusations of "racist" and "bigot" are beginning to lose their sting on Conservatives.
I believe one still can not post material from sites like V-Dare or American Renaissance here. So multiculturalism's basic rules are still binding on people who claim to not believe in them. The deeply ingrained rules of Multiculturalism may be the harder of the two problems to solve.
The mass immigration into the EU and Britain is a plot by the transnational leftists and the wealthy global elites to destroy the idea of the nation state, and their domestic populace, and institute a world government. They want to do the same in the US, but the US is just a bit behind Europe in this goal.