No that will work on a real machine. Just type it in and RUN it
Takes about a minute / minute and a half or so to 'work' as it has to 'draw' onto each character row.
At the end it will show the normal default font (or whatever was chosen at the time) then the 'new' one and leave the new one active. See POKE's provided and the SAVE if needed.
Note you can run it again to thicken the font again! But it gets very messy.
If you're stuck and can type blind then POKE 23607 , 60 and (not needed here but worth knowing) POKE 23606 , 0 should restore normality.