just to add to bmacattack33. I use the properties page to make this change online. You can add a 1 to the end of the tag name on the property page and it will change all instances in program to {tagname1}
no need to do search and replace. You can also change in the tag file by double clicking tag with the same results. Then make new tag in correct scope or data type and then you have to go thru program and remove the 1 from all instances. Once all instances have been changed you can delete {tagname1}. If it will not let you delete then there are still instances left. If tag is being monitered by another resource then changes are not allowed. ie: HMI or other