Hi Kevin, thanks for writing!
Well you’ll have to do something with the 20%. The idea is to invest it (I’ll write more about where to invest starting June 20th).
So let’s say you make $5,000 a month. Automatically you remove 20% off of it — $1,000.
That $1,000 will be invested. If your 401(k)’s asset allocation is done right (index funds) you’d better invest it through there since you’ll save on taxes. I wrote about the correct order and more details here.