Please refer to the Ends page in the assembly guide as well
When you are covering the ends of the structure, there are some similarities and some fundamental differences when you are covering with plastic or with tarp.
The aluminum wirelock channel must be installed on the top side of the hoop before you start the cover. You start at the base of one side and go continuously over the peak so that there is not an edge at the peak. Your cover will be a rectangle and you must double check if the two ends were supplied as one piece or not. The framing must also be in place before you are putting on the cover.
The cover gets fastened, temporarily, at the base first on either side of the door and then pull out to the corners. If there is ANY wind, do into the wind side first. Please remember that whenever you have wrinkles or folds, you will pull 90 degrees to the wrinkle. Excess on the end covers will only get trimmed off after the roof cover is on as well.
If you are covering the end with plastic, you would go with the extra of your rectangle and fasten it temporarily to the back side of your framing. At the very most, at this stage you will put part of a wire insert on either side of the peak. When the cover is sitting smooth, you can put some strapping on the vertical framing to hole the cover in place.
If you are covering the ends with tarp, you will need to remove the wirelock channel first. This may seem like double work, but the channel is now curved to the building with the required screw holes. The end tarp cover is sandwiched between the hoop and the bottom of the wirelock channel. When you pull the tarp over the peak, you will reinstall the wirelock channel from the top and work down. If you do the left, right or bottom first will be determined by where the wrinkles are (if any).