The options are disabled because you selected the option Prevent access to options for this block set at times when these sites are blocked and now those sites are blocked (hence the options are currently inaccessible). The purpose of this option is to allow users to prevent themselves from easily changing the settings once the sites have been blocked, but in a way that doesn’t prevent access to all LeechBlock options.
If you really need to change the settings for the block set before the blocking period has ended, you can email leechblockng@proginosko.com for instructions, specifying which browser you’re using (Firefox, Chrome, etc.).