you cannot do "你可寄挂号信通知房东:如在十天内房东仍不维修,你可请公司维修,然后将费用从房租中扣除。" or " 通知租务法庭;然后将维修的费用在你的房租里扣除。" otherwise you may be at the risk of canceling the lease. The correct way is to inform your landlord to fix the problem within 10 days by registered letter. If she/he does not fix, you go to regie du logement and request for rent deduction. Good luck.