The jammer is actually on the roof of this very building. It's above the northern wing. Climb up so you look over the jammer and then you can jump down and fight the enemies. You should be careful here because while none of these enemies have weapons, they can get weapons from the green stack of boxes by the wall. If you hear some kind of siren, it means that someone is trying to get a weapon out. This person should be your priority because if they get a weapon out, it can end this battle pretty quickly.
Run to each of the screens on the jammer and break each one. There are three. But wait, there's more! The other jammer is just north-east of the museum. You should see it in detective mode. You may end up approaching this building from a lower level rather than higher because of the low lying buildings around it. It may be preferable to go around it and get up higher before trying to take the enemies down. There are four of them. Two are together right next to the jammer and can be taken down with a baterang and glide. The other two will come running and if you leave you can probably do the same thing to them to quickly clear the area. Disable this jammer like the last one.
