How to delete and rename a key=value?

I created a store like this:

vault secrets enable -path=vault1 -version=2 kv

Then I put a key/value in it:

vault kv put vault1/test mykey=myvalue

How can I delete or rename mykey?

I tried already: vault kv patch vault1/test mykey=null but it does not work just create an entry: mykey=null

Thanks

To remove the whole entry:

vault kv metata delete -mount=vault1 test

To modify test :

vault kv put -mount=vault1 test mykey=myvalue otherkey=true

Remove mykey:

vault kv put -mount=vault1 test otherkey=true

change mykey:

vault kv put -mount=vault1 test mykey=mykeyothervalue otherkey=true

Each time you have to give the whole value of test entry.