Grab the VAX/VMS 5.5-2H4 ISO: http://osarchive.org/os/vms/OS/5.x
Put the ISO on RQ0 and the boot disk on RQ1, or vice versa. Boot from ISO and:
back/ima/ver dua1:vms2h4055.b/save dua0:/init
Wait until it completes, then boot from your boot disk. Keep the ISO attached and go through the prompts.