Email the signature to yourself and open the shared signature link on your phone.
If you’ve received a shared signature link, simply open it.
Copy the signature to your clipboard.
Open the Yahoo Mail App on your Android device. In the top left, press the menu button, then press Settings.
In the Settings menu, scroll down until you see Signatures and go into it.
Remove any text that is currently in the signature text area. Press and hold over the email signature text area until a pop up box comes up and then paste the new signature.
Your new email signature is now installed! Test it out by composing a new email to make sure it looks correct.