Moving During the Nine Days

Concerning the law of Mezuzah: I have in my possession 3 Mezuzot that my parents lent me (the parents from both sides paid for them and I believe they said it was a loan so there wouldn't be a problem to remove them...). The Mezuzot are affixed in a rented apartment that I am now leaving after six and a half years, the Mezuzot have not been checked since the wedding. My question is, can I remove them in order to affix them in the apartment to which I am moving, which currently has no Mezuzot (the tenant who was there took his Mezuzot with him)? What is the most proper way to handle this?

Shalom!
The most proper thing to do is to take your mezuzot for inspection, and to place there Mezuzot from a free loan fund (Gemach), and to tell the next tenant that it is his obligation to bring his own Mezuzot and return the Mezuzot to the free loan fund.

Shulchan Aruch, section Yoreh De'ah, chapter 291, §2