Klonopin is longer lasting so it would be better for tapering off since you only need one dose a day. Clonazepam is about two times as strong as ativan so youd need to quit ativan and drop to 0.75mg clonazepam.
Do you have 0.5mg clonazepam pills? Id recommend dropping 10% per month. Cut the tablets in pieces and weight them if you have a scale. Otherwise just cut them and eye ball the dosages.
When you get to 0.125mg you could drop off.