windows NT mirror

I have a windows NT PDC that has two hard drives one is a master on ide1 the othe a master on ide2. I want to use a tape device for backups the tape needs to be on ide2 with no other harddrive. Simple question what is the best way to break the mirror. can i just take the second hard drive off. should i break it in disk administrator. If i romve the second hard drive and the first one failed would i be able to boot into the second. I really cant crash this server $$$. Thanks for any help.