In order to re-designate the log file location, you would have to have access to the site administration side of QC/ ALM. If you have access to the sire administration side of QC/ALM, then log into the site administrartion side and select the server tab along the top. One the server information is displayed, select the server on the right side menu, and then when the information populates on the right side, select the location boxes and populate with the patch information for the newly desired log file locations. This can also be done for the server logs as well. If you would like all of the previous logs to be in that location as well, you will need to copy them over manually.
I hope this helps and answers your questions,