Once you've purchased your new drone cords you will need to fit them.
Drone cords need to be fitted so that the drones are not too close or too far apart. The quickest way to get an even fit is to start out with one tassel beside the stock on your outside tenor drone. Run the cord up to the outside tenor bead and tie the cord in on either side with cable ties or thread.
Now run the cord from the outside tenor top down to the bottom of the ferrule and use this spacing to tie in the middle tenor (spacing around 6"). Tie as before. Again, measure down to the bottom of the middle tenor ferrule and use this for the spacing between the middle tenor and bass mid-section. Tie the bass mid-section at this location.
Run the cord up to the top bass section and tie it in with a little bit of slack in the cord so that you can take the top section apart easily. The remainder of the cord can be left as is if they are not too long, or you can tie the end of the cord back onto itself between the top and middle bass sections.
PS: For a superior finish, you can use a needle and thread to secure each cord with a small stich, or use small clear cable ties as a quick alternative.