@Mukiha - I suggest you increase the rent to 100k with 5k penalty for every day delayed after deadline. Give the chap one months notice before 'implementation'. No court will stop you. If he doesn't like the new terms, he should move - and that is what you want any way. The rent tribunal - whatever it is called - covers low end market - used to be 2,000/= and below - so it will not be used against you.
You can also organize visits by "auctioneers" every weekend - when he has guests over - to remind him of his unpaid rent bla bla bla. If he has any shame he will leave ASAP!
Make sure you report back here. What you did and how it went.
Never count on making a good sale. Have the purchase price be so attractive that even a mediocre sale gives good returns.