I tried it in a lab, here is the result.
You need to reimport the certificate and might have to reconfigure the service where the certificate should apply.
Import certificate:
/certificate import file-name=crt.pem passphrase=“myPASS”
Apply certificate to HTTPS services:
/ip service set www-ssl address=0.0.0.0/0 certificate=crt.pem_0 disabled=no port=443