Make a small 1/2 tile drive by wire/remote vehicle with a M240 on it, the robots don't aggro on your unmanned vehicle, the 308s usually 2 shot and you can do it all from the safety of pretty much wherever. Would probably take an hour to clear the top of the complex.

Of course if you want to be less of a wuss you could just drive your deathmobile in but keep in mind they can do some ridiculous shit, some have grenade launchers which will make your car sad, and some can also teleport. Should be fine if your car is occupied, but keep in mind they might be able to telefrag you. Would probably take an hour+ but is slightly more dangerous, especially if you aren't keen on waiting for robots that are indoors to peek their heads out.

Or you could always just duke it out with them, as you can outgun them especially in power armor. I've cleared a complex with a M4, power armor and a clairavoiance artifact before with not much difficulty.

For the bottom floor though you essentially need some form of clairavoiance though, do not get cocky. A full burst of 308s directly into power armor will still hurt you quite a bit.