Uploading a combat log
This is going to be really easy : click "Browse", choose a combat log on your hard drive, then click "Start Parsing", and that"s it ! Your new report is available on your WMO account.

Your combat log is usually a file named WoWCombatLog.txt, but you can add other log files from your guildmates, with other names. You can also add directly zipped combat logs. In case of larger(over 300M) log files, WMO will suggest you split it to smaller first before upload it(see above).
If you've checked the box "Archive and delete the original log file after upload", WMO will zip your log and put it into your work dir and then delete your txt log files after the report is generated. If not, you will need to handle these files manually.
You can add a name or comment to your raid, but don't worry if you forget to choose a name/comment, you can still change it after your report has been uploaded.