You can’t directly do it, looking at the specs show us that the value can be set, but not over-written (such is the standard definition of a constant), however there are a couple of somewhat hacky ways of unsetting constant values.
Using scope
const is scoped. By defining the constant in a block it will only exist for this block.
Setting an object and unsetting keys
By defining const obj = { /* keys */ } we define a value obj that is constant, but we can still treat the keys like any other variable, as is demonstrated by the examples in the MDN article. One could unset a key by setting it to null.
If it’s memory management that is the concern then both these techniques will help.