Please check the detailed tutorial here. The following concise steps are:
Add the following options to the Qtum wallet configuration file. You may check official document for reference.
uacomment=REPLACE YOUR QTUM ADDRESS HERE
Start Qtum and keep it running. You need to restart it after changing your configuration file.
When the event ends, there will be total of 500 QTUM dispered to the top 100 nodes with the most cumulative online time and hasn't won any awards nodes.
This award will be counted by the user’s IP, when there are several different effective nodes that run under the same IP, the one that stays online the longest will be selected automatically.