-You must write your code so that we can choose a page replacement policy
-at compile time. By default, the LRU-like algorithm must be in effect,
-but we must be able to choose random replacement by inserting the line
-@code{#define RANDOM_REPLACEMENT 1} in @file{constants.h}.
-@xref{Conditional Compilation}, for details.
+You must write your code so that we can choose a page replacement
+policy at Pintos startup time. By default, the LRU-like algorithm
+must be in effect, but we must be able to choose random replacement by
+invoking @command{pintos} with the @option{-o random-paging} option.
+Passing this option sets @code{enable_random_paging}, declared in
+@file{threads/init.h}, to true.