You can't modify the original Top 100 playlist. The workaround to modify the playlist is to select all the songs in Top 100 and create a new playlist from the selection. After that you can modify the newly created playlist as you like.
Workarounds are nice, but this is a once a year bonus playlist from Spotify, would be very appreciated to provide the ability to tweak...In my case I listen to newage music sometimes at night to go to sleep, and all these (approx 20) ended up in my 2018 wrapped, MAKES MY WRAPPED UP PLAYLIST COMPLETELY BIZARRE & USELESS.
Have you discovered a way to correct this on your end? I keep getting prompts to accept the user who suggested to copy a playlist minus songs I don't want over to a new playlist, but this isn't a solution in my books and defeats the whole process!!?