How can i change and customize the special characters on my keyboard?
Is there a way to do this without creating a new keyboard layout? 


You can do it by defining Service:


Run Automator
Choose a type for your document: Service
Check Text from Library on the left
Double click Get Specified Text
On the right check Output replaces selected text
Paste your character into text editor window of "Get Specified Text"
Run System Preferences and choose Keyboard -&gt; Keyboard Shortcuts
Choose Services
Find your brand new service and assign it a shortcut


Or with key bindings.