Simply login to the Admin Panel of your Web Store by to your website and typing /admin after the .com part... like this:
NOTE: You must register as a user on your own Web Store first and then give yourself admin access before this works but once you're in, simply click on KG Plugins in the top menu. If you haven't done this, register as a user on your own web store and then use the Admin Panel access within LightSpeed in order to give yourself administrative privileges.
Here, you'll see Manage Customer Categories and Manage Customers.
Click on Manage Customer Categories and you'll see a short list of the different categories that have been created and the discount that someone assigned to the category will receive. To change a percentage, just click on it to edit the number.
Next, click on Manage Customers and search for the desired customer by typing some information into the search row (which is the first row just under the headers but before the data).
Remember, the customers here may not be the same as the ones in your LightSpeed system. Your customer needs to register on your website first. Once they register, then you should be able to find them in this list.
Once you are able to find the customer, assign a category to them and they should be able to get the special pricing the next time that they login.