Just pass it through generation as you would any other scientific information. Wiki mentions that the problem is:
Unfortunately, there is no method available to continuously providethe necessary knowledge about the location of nuclear waste overthousands of years. The culture of earlier centuries becomesincomprehensible when it is not translated into new languages everyfew generations. National institutions do not exist longer than a fewhundred years. Even religions are not older than a few millennia anddo not typically hand down scientific knowledge.https://en.wikipedia.org/wiki/Human_Interference_Task_Force
But this is nonsense because people who call this "a problem" seem to focus on what they perceive as "important" - i.e. religion, which is inherently subjective and open for interpretation, and thus easily "mutated" with each generation, while scientific knowledge stating objective facts survived longer lengths of time undamaged. Statements of Pythagorean theorem or Archimedes' principle, for example, is about 2500 years old. There's NO problem.