Let's start with Summit. First, you want to get into the main computer room. Get on top of the console with wooden crates, then sprint and jump on to the walk way. Now go across and break the window. Sprint and jump on to the large platform. For this its good to have a sniper, camp there.

Now to Firing Range, first you want to get into the garage and go up the stairs. You will get to the little window and you will see a little beam. Run across that and get to the sand bags. This is good if you have a red dot sight or a sniper, camp there.

Tip: go on those maps yourself with no one else and keep trying so you get quicker and quicker.