Review list of repos which have been mirrored, paying close attention to the target column which outlines the chipset. Make a list of the NAME and TARGET columns; this is important for later.
Ensure the repo is not set to currently mirror, or the deletion will fail (Alt-M)
Once you are out of yast, run, # smt-repos --delete
Copy the corresponding ID number (second column) which match the NAME and TARGET columns (beware, SLES11-SAP is different than SLE11-SAP).
Once you have the list, you can plug in the ID number one at a time to confirm the path contains both the NAME and the TARGET you wish to delete:
Delete repository `/src/www/htdocs/repo/SUSE/Backports/SLE-1
NOTE: The command smt-repos --delete can only accept one (1) ID at a time.