diff --git a/README.md b/README.md
index 35784d3..1d6b4c3 100644
--- a/README.md
+++ b/README.md
@@ -207,7 +207,19 @@ ssb#  ed25519/085A93EB5D85EE54  created: 2026-03-10  expires: 2035-03-08
 
 ```
 
-Any time you change the yubikey you use you have to delete (`gpg --delete-key`), refetch the key (`gpg --card-edit fetch`), and set the trust to full (`gpg --edit-key 01B157D574FEDBB2 and then put ultimate trust in the key`)
+~~Any time you change the yubikey you use you have to delete (`gpg --delete-key`), refetch the key (`gpg --card-edit fetch`), and set the trust to full (`gpg --edit-key 01B157D574FEDBB2 and then put ultimate trust in the key`).~~
+
+[A direct way](https://github.com/drduh/YubiKey-Guide?tab=readme-ov-file#using-multiple-yubikeys) is:
+```
+gpg-connect-agent "scd serialno" "learn --force" /bye
+```
+
+
+Finally, in the NIX environment I use for my mac all the GPG tools live in /Users/olaf/.nix-profile/bin. Hence, for mailmate I need to set:
+
+```
+defaults write com.freron.MailMate environmentVariables -array '{"enabled" = :true; "name" = "MM_GPG"; "value" = "/Users/olaf/.nix-profile/bin/gpg";}'
+```