Sto wrote

Just have one person doing the cutting (probably the tallest person is best). Having the other friends looking out for authorities and nazis is a good idea. Depending on how far up the poles the posters are, you may need something to stand on. Rather have it be something you can ditch if you need to run.

Having a general sense ahead of time where you will escape to is a good idea. If you might get followed by a cop or security in a car, picking a spot to run through that a car cannot move through is good.

Decide for yourself ahead of time whether you will go down for your friends if the cops catch you.
This is important in the case that among you there will be different punishments for being caught. If one of you is an immigrant, for example, they might risk deportation by participating and its on the others to make sure that they get away.
With this in mind, if you end up being followed or chased, you can decide whether splitting up is a good idea.

As Tequila_Wolf said, running around with a bunch of nazi election posters is incriminating. I think it makes more sense to destroy or deface them on the spot. I am not sure how strong this corrugated plastic is, but maybe taking a nice stanley knife to it and leaving it in pieces on the floor would work.

If you want to be overprepared, having a lawyer's phone number written on your arm is another thing you can do.