Most of it can be translated directly, especially if you can dispense with the rhyming. A few parts require some special attention but can be translated.
I do not speak French, but most of the clues do not rely on wordplay or cultural cues that would cause any difficulty in translating them. Direct translation would probably mess up the rhyming, but little else. I explained the meanings of all the clues in this answer, so refer to that for specifics.
There are three potential translation pitfalls. They are:
"If you find the false, you'll find the true..."
True and false are often used in English to indicate the veracity of a fact or statement, but in this case, false is used in the sense of "fake" and true is used in the sense of "genuine." It is important that your translation convey those connotations in order for the players to properly interpret this clue. The clue means that if you find the fake door at are 23, you will find the genuine secret door behind it.
"the throne that is key and keyed..."
This might throw off your translation since the throne is "key" (adjective--meaning critical or important), not "a key" (noun meaning something that opens a lock). The throne is also "keyed" in that the scepter touched to a certain part of the throne acts like a key in opening the passage behind it. If the French word for key is not both an adjective and noun, like it is in English, you will want to translate this carefully so your audience would not interpret the throne to be a literal key that opens a lock.
"You've left and left..."
The first "left" here is a verb. If you get rid of the contraction, it reads "you have left." The meaning is that when the party has left area 30, they should search to their left (direction) and find the keyhole. Many people misinterpret the clue to mean "take two left turns" and that was probably intentional on Gygax's part, because after leaving 30 and turning right, two left turns will dump them out a magical one-way door to an area earlier in the dungeon.
It may not be possible to translate this clue into French in a way that carries that misleading double meaning. What you will want to do is write it in a way that subtly suggests characters search for the secret door to 33 after leaving 30, but also might trick them into following the corridor to the one-way door. Note that the clues are generally in the order that the party will need them, and it is likely the party will pick up on this. So whatever clue you place after the "iron men" clue, the players will be thinking of that as their next clue when they pass the secret door that iron statue hides.