there are couple of ways. easiest way is pasting your script into the mini command line.
1. Hit tab key to focus mini command line,
2. ctrl+v to paste your copied script.
3. Hit enter to execute your script.

also you can go to "options/shortcut keys/add" to add a new hotkey then paste your scipt into "Command" section and write down any key combination you'd like in "Key" section.

also you can save your script as a .js file and run it using scipt's name.
for example; your script is called MyScript.js and its placed in /commands folder. You simply type MyScript in "mini command line" and it's executed.