You should place the new file in your /usr/local/haast folder, and remove the old file called haast.license or rename is to haast.lisence.old
Upon next HAAst service restart the new license file will be used. The new license allows you to install new upgrades to HAAst, and benefit from new features as they are released. The new license file will also reflect the updated expiry date for your maintenance agreement (in terms of support and upgrades).
In case you have multiple HAAst license files (following one or more maintenance agreement renewals) then this is how HAAst picks which license file to use: When HAAst starts it will first look for a file called haast.license and use that as the license. If that file does not exist then HAAst will look for a file called haast.XXXXX.license where XXXXX is your license number. If there are multiple files that match this format then HAAst will choose the one with the highest license number (most recent). If you have multiple HAAst license files and you want HAAst to use a particular one then you can create a symlink from haast.license to the file you wish.