At the bottom, start by looking for a set of crates against the same side of the wall as the mega turret. You can't miss them as long as they haven't been destroyed. After space jumping on the crates, do an l-lock space jump toward the top side of the same ledge the mega turret is attached to. If you can't make the jump or the crates were destroyed earlier, you can still get on that ledge, you'll just have to take the longer way around involving the floating platforms.

Once on the ledge, space jump to the spot Samus aims at with R in the picture, then do another to reach the central platform in the middle of the room.

Now for how to reach the ice door at the top when starting from the middle. Go over to the large window at the back and notice how there is a vertical thing made up of bars at both ends of it. The one you want to use is the one on the same side of the room as the plasma door at the bottom (although the other one works just as well). Space jump on the bar in the below picture. As usual, Samus is aiming at the spot with R.

After landing, turn to face the window, as if you were looking out from it. There's an invisible ledge against the wall that is just ahead of and above you. L-lock the view and jump off the bar while moving right, then use your second jump about a half second later and move in the shape of a backwards C (starting at the bottom of the letter). Even though it looks like there's nowhere to go, you'll land against the wall, from which point you want to turn around to face the ice door in the middle of the room and make sure that your view is the same as this picture.

The last thing to do is jump off from where you're standing and move slightly left, then use your second jump to move forward and to the right so that you'll land on the next highest bar in your view. This time, the motion you should be moving in is basically just a letter C. Space jump to the platform which is now right next to you and you're done, as you've reached the upper part of the room where the spider ball track ends.