The second slide sums it up nicely.
Basically the idea is: Every single western nation has a artificial flow of immigrants for a reason. The native population stagnates and cannot sustain itself anymore, so a demand for labor rises. The countries meet this demand by taking in immigrants to keep the population growth up. Eventually the immigrants take over and thus "ethnic replacement" is complete.
The problem I have with this is that the culture and quality of life that comes with a homogeneous population are far more important than this goal of "INFINITE SHORT-TERM FINANCIAL GROWTH" desired by the rich.