Does your family understand cryptocurrency too? if not yet available, you should provide education to the closest and most trusted family, for example, your husband or wife, your brother or sister. This is as an anticipatory step so that the inheritance can be well utilized.
There is a simpler way. You create a document containing letters, instructions, etc. You can also include a private key or password to access the wallet containing your inheritance. Then you can ask for the help of a trusted lawyer, or to make it simpler to keep it with other important papers.