The courier ship emerges from hyperspace near an anonymous binary red dwarf system, transmits its authorization codes, waits for approval and then heads for orbit.
Visser 3 paces.
It is, inevitably, massively inconvenient to do this, every time, and particularly to do it without anyone finding out. The tight compartmentalization of the Yeerk command structure helps a lot, of course. Of the minimal personnel on the ship, only his lieutenant is a member of his usual staff; the rest don't expect to have clearance to know what the Visser is up to or why he needs to visit a secret research facility fifty light-years from anything important. For her he at least needs an excuse, and has one, and from there it's only a moderate hassle to slip off for two days worth of 'meetings' that she isn't cleared to attend. (Mhalir still thinks in Andalite days, though the ship's internal timekeeping is currently set to the Earth day-length.)
The equipment from a twenty-year-old 'abandoned' research project, dismantled according to the records, still needs an engineer to operate it, since Mhalir will be outside of his host body and unable to communicate while it's in process. And medical personnel to keep Alloran safely sedated for two days, but that's easy. Mhalir brought his own engineer on the courier ship with them, from Earth, someone he chose for both her skill and her utter lack of context. She was born on the Pool ship in Earth's orbit and has never been elsewhere, and is doing an admirable job of not asking any questions, it's need-to-know and she knows all she needs to. The actual protocol she'll be following is designed to be a little misleading, if she does make any guesses she might conclude this is some kind of bizarre cryptography project. Even if she does stumble toward the truth, she won't know enough for it to really matter.
Alloran cannot read Mhalir's thoughts, thankfully, and knows only what the Visser has actually covered in writing or conversations, which is the cover story with the other research. For any more sensitive planning, Mhalir has made sure to block Alloran entirely from his own senses.
After this, once he has the file saved and packaged, he'll take a different courier ship and fly out alone, leaving a message for his lieutenant that an 'emergency' called him away and she should wait here for his return. He just needs to make sure Alloran doesn't see the coordinates he gives the computer, or any distinguishing features of the system where they'll be arriving, or what exactly Mhalir leaves there. It's a week's hyperspace journey each way, though the actual dropoff won't take long.
Two months, end to end, that he's going to be gone from Earth. It's worth it, he thinks, when the last file he concealed underground on a frozen moon is five years out of date. Safe enough, he's finally gotten Visser One's mess under control, and he doesn't know when he'll have the opportunity to do this again.