Firstly, your title is Software Engineer so you should be as away as possible from databases and ask a DBA for help when needed.
Secondly, if you are training yourself to become a DBA and assuming you are talking about a test or lab server there are lots of ways of corrupting your database to simulate a catastrophic situation.
The easiest one is just to imagine your database got corrupted so you go ahead and restore it.
If for some untold reason you really want to corrupt it look at the O/S level for the mdf file and overwrite it with a text file -or any file you want.
Last but not least, in your post you say you know how to restore it so; restore it.
Pablo (Paul) Berzukov
Author of Understanding Database Administration
available at Amazon and other bookstores.Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.