You have two options. One is top-down, renegotiation of your position. The other is bottom-up, scorched earth policy. I suggest you implement both, simultaneously.
Top down. Advise attackers that corp is under new management and you are open to negotiation. Make your position stronger by first booting previous CEO from corps, if they have not already left. That will show up on their profile and make your position stronger.
If the wardec was more business than personal ie they just do not want competitors in “their” system, your position is still weak and your options much more limited. For example, you can offer to close any public facilities, and make it corps-only, if that is what their beef was. Or, you can offer to sell (give) them refinery but keep citadel, or vice versa. If they will not accept any of that, you are stuffed. In which case, go to Plan B.
Plan B starts with booting everyone from corps. The structures are going down anyway, so you want to maximise recovery for you, and limit gain for attackers. (I am assuming here that corps only has the two structures?). So, at this stage, everyone out. All assets out.
Any rigs are obviously sunk. And chances are that once a structure has been reinforced all the modules are sunk too (you usually cant remove them after reinforcement). If they have only reinforced one structure then strip the fittings from the other. one. RIGHT NOW. You dont have to move them (yet). Simply unfit and put into structure inventory. After that, you don’t have to do a thing.
If you can move all of the “liquid” assets, fine. If you can’t, they will be moved for you - eventually - under asset safety, but you will have to pay a % to get them back. But, because you got them for nothing, you wont care., as you will be net better off. Plus, that is another reason for booting everyone else, RIGHT NOW. You get corps isk which might possibly be enough to pay to redeem the assets afterwards.
After the dust has settled, if you wanted to distribute all the net assets back amongst your previous corp mates, that is up to you. But at this stage, play hard ball.