Fallout 76 is a highly popular game, and many players are eager to try and complete the entire scoreboard in a single day. It may seem impossible, but it is definitely possible, and it is quite simple. All you need to do is take advantage of the junk you already have, as well as a few other tricks, and you can complete the scoreboard in one day. 

The first step is to go to the Challenge tab and select the Combat challenge. Here, you will see a list of all of the challenges you need to complete in order to earn points. You can complete these challenges by using the junk you have on your account, as well as crafting and modding weapons. Once you have completed all of the challenges, you can move on to the next step. 

The next step is to make a new Fallout account and transfer all of your junk to it. This will allow you to redo the challenges on your main account, and thus earn more points. You can then use the gifting system to send the points from your new account to your main one. To do this, you will need to make a support ticket on the Fallout website and request to transfer points from your new account to your main one. This will take a couple of days to process, and once it is done, all of the points you earned will be added to your main account and you can complete the scoreboard. 

Finally, if you are not rich in junk materials, you can also enter giveaways hosted by other players who are willing to give away junk materials in exchange for points. This will allow you to craft and mod weapons and thus earn more points. 

In conclusion, completing the scoreboard in Fallout 76 is possible, and it is quite simple. All you need to do is take advantage of the junk you have, as well as the gifting system, and you can complete the scoreboard in one day.