Perhaps it's more fitting not to erase these names, but rather append swastikas to them, guiding readers towards a plaque that elucidates their heinous crimes as Nazis. In this way, the monument will persist as an enlightening reminder of who exactly the "victims of communism" truly are.
I'm planning on visiting Ottawa someday to visit the Canada Aviation and Space Museum. I think while I'm in the area I'll bring a folding chair and bottled water and just sit by that monument with a sign. I'm torn between the spell-it-all-out "NOT ENOUGH DEAD NAZIS" or an inflamatory "THEY DESERVED IT". But I'm open to suggestions.
You could also spray-paint "REST IN SHIT NAZIS, L " on it
How about "Eat shit, fascists!"?
Oh, or maybe "Let's bump up those rookie numbers!"
they deserved it is funny
I may make multiple signs. One of them is definitely going to be the old wikipedia notice of "This list is incomplete, you can help by expanding it."