I haven’t really been able to find a guide on how to do this well. I did it incorrectly at one point. a few years back and it became quite expensive.
I understand that there’s a 7-day timer, get all your stuff out, etc. Beyond that, though:
From what I understand, as soon as you attempt to unanchor a structure in Hi sec, you will get wardec’ed.
@Raketefrau be sure to link us the lossmail 
Here is some more info:
I never got a chance to unanchor my station, as soon as the core went in they attacked. This is why I view stations as pinatas in space. I won’t bother with them any more.
However I did watch a lot of videos about stations. One video showed that he kept decommissioning and resetting the timer to confuse the crap out of those interested in ganking the core. The core drops out at the end of the timer and anyone can nab it. You better be there for the main event. Hope that answers the question.
Fly safe o7
Don’t unanchor it. It’s that simple. Let it run with one service module, maybe it can generate some content or can be used/sold in the future.
If you really want to unanchor it which is the worst decision in my opinion make sure to decommision it and reset the cycle a couple of times so it’s unclear when you really unanchor it.
Remember that probably everybody that put 1 Tritanium (some hs pirate groups) inside the station gets a message that the thing is being decommisioned.
You could also consider selling/transferring the ownership to someone else, leaving it as-is. Or, when messing with the decommission timers, choose the final one to be a time that’s less likely to be interfered with in your system (low activity, or right after downtime or something).
My patchy understanding of the process is, if the structure has been attacked/reinforced, you can’t change fittings or modules etc. If it is running normally, you can offline and unfit the various modules (not rigs, those are locked in). You want to leave at least one module powered and running though, as per:
" * If a structure has at least one service module online, it is considered to be in “Full Power” mode and will undergo an additional reinforcement cycle should it come under attack. If no service modules are installed or online, the structure will be considered to be at “low power” and will be considerably easier to destroy. More details on structure vulnerability can be found within the Upwell Structures Vulnerability States article."
This part of the game is seriously broken. There’s no good reason to make a Corporation a target for griefer corps, simply because they have a structure. Calling it “High-Security Space” is the biggest joke in the game. You may as well rename it Portland.
The safest way to unanchor a Citadel is to not anchor one in the first place…
They will war-dec you 24+ hours from the time it’s due to be unanchored and then show up in force to grab it as it unanchors. The massive CCP flaw is that the game allows anyone to drop off a piece of tritanium in your structure, even though they have no docking rights and they then get a notification when you start to unanchor it even though they have no right to such a valuable piece of intel.
This complete and utter stab in the back is ccp’s way of saying you can’t have anything nice and that the engine is driven by loss. Your loss. Personally, I just consider them all dead when I anchor one, but it’s a terrible way to do things.
No different than undocking. Each and every time you do, you might as well consider your ship a loss. This is a PvP game, after all.
If CCP made it more difficult to kill a Citadel, or more difficult to wardec another player corp, then we would have tens of thousands of random single-player Citadels strewn about all of high sec.
Off topic since everything I ever anchored in hs was a write off just to see if I could make my isk back before it got destroyed.
In the wh I “creatively acquired”, I watched them take down their citadel as they left. They got the citadel, I got the containers. Far more valuable! 
Agreed. We need to move back to the old wardec rules that weren’t tied to structures. This is just one of many reasons that wardec “reforms” have been a failure. Roll it back.
Haha…
This is a valid point, although the addition of the core is a deterrent to onlining one in of itself.
Almost every response here you should ignore.
When it unanchors the modules, fuel and core will be in a can alongside the unanchored structure itself.
Start the unanchoring whenever you want, ideally when there’s not someone outside the structure. The chances of someone seeing this as very small. And don’t pull the fuel/ mods - this will make it low power and THIS is what alerts people to it being unanchored.
Even if someone in the week realises it’s unanchoring it’s almost impossible to watch this for a full week. If you see similar names in local in that 7d window that are watching it then reset the timer a few times randomly to make it pointless for them to pounce on it.
People are not war decing unanchoring stations, they do so when people pull the fuel and mods at the same time.
People with assets in your structure only get a notification when the thing unanchors, not a warning. Just be online with your hauler at the time it unanchors (not 5 mins later) and you’ll be fine.
Don’t you guys get tired of this rhetoric?
What would be the drawback to that?
Agreed. CCP lacks the vision of a prosperous society.
Loss doesn’t equal growth.
Roll back the WD mechanics.
Because it would accomplish nothing other than littering high sec. The same as the hundreds of mobile depots and cargo containers littering every jump gate with ads and spam.
Yes, on that we agree. Roll back war dec mechanics to when we could war dec anyone, at any time, for any reason, or no reason at all, whether you own a structure or not.
Not the worst idea…